291 January, 2004 DOS Times - Vol.9, No.7 CONTENTS DOS TIMES Editor-in-chief Dr. Jeewan S. Titiyal Associate Editors Dr. Harish Pathak Dr. Harminder K. Rai Dr. Vijay B. Wagh Editorial Advisers Dr. K.P.S. Malik Dr. Pradeep Sharma Dr. Ramanjeet Sihota Dr. Ritu Arora Dr. Dinesh Talwar Special Correspondents Dr. Ajay Aurora Dr. Rajib Mukherjee Dr. Anita Sethi Dr. Devender Sood Dr. Pradeep Venkatesh Coordinators Dr. Anurag Dr. Anand Dr. Madhusudan Ms. Monica Choudhry Dr. Pranav D. More Published by Dr. Jeewan S. Titiyal for Delhi Ophthalmological Society Printed by Computype Media 208, IJS Place, Delhi Gate Bazar, New Delhi-2 Tel: 23284148, 23259312 DOS Office Room No. 476, Dr. R.P. Centre for Ophthalmic Sciences, AIIMS, Ansari Nagar, New Delhi-110029 ( : 26589549 Fax : 91-11-26588919 Email: [email protected]Website : www.dosonline.org Keep April 3-4, 2004 Free for ANNUAL CONFERENCE Delhi Ophthalmological Society of EDITORIAL ................................... 293 FOCUS w Age-related Macular Degeneration ............................... 295 Rajvardhan Azad , Tara Prasad Das, Cyrus M. Shroff, Dinesh Talwar, Sanjeev Nainiwal CURRENT PRACTICE w Phakonit Thinoptx Rollable IOL ................................................ 299 Amar Agarwal, Athiya Agarwal, Sunita Agarwal REVIEW w Problem Situations in Retinal Detachment Surgery .................. 303 Cyrus M. Shroff, Ajay Aurora APPLIANCES w Ultrasound Biomicroscopy in Glaucoma .................................... 307 Tanuj Dada, Ramanjit Sihota, Harinder Singh Sethi REVIEW w Fitting of Soft Contact Lens ...... 310 Jeewan S. Titiyal, Ramkishor Sah, Rajesh Sinha MANAGEMENT PEARLS w Contact Lenses Complications their and Management .............. 316 Jagjit S. Saini w Management of Convergence Insufficiency and Accommodation Anomalies ..... 320 Sachin Kedar, Pradeep Sharma COLUMNS w Letters to Editor Practical Tips to Manage Post- Operative Endophthalmitis ..... 323 Sanjeev Naniwal, S.P. Garg, H. K. Tewari w Journal Abstracts ........................ 324 w DOS Quiz No. 7 .......................... 327 TEAR SHEET-7 w Ocular Side Effects of Systemic Drugs ............................................ 333 Deven Tuli
w Letters to EditorPractical Tips to Manage Post-Operative Endophthalmitis ..... 323Sanjeev Naniwal, S.P. Garg, H. K. Tewariw Journal Abstracts ........................ 324w DOS Quiz No. 7 .......................... 327
TEAR SHEET-7
w Ocular Side Effects of SystemicDrugs............................................ 333Deven Tuli
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EDITORIALDear Friends,
At the veryonset, I on be-half of DelhiOphthalmo-logical Societywould like towish all ourmembers avery happy
and a prosperous new year.Every coming year is a new chal-
lenge to all of us. We have to adaptand imbibe newer techniques, keeppace with newer technologies, up-date our knowledge to the currenthappenings and the most tough ofthem is to keep our patients happyand satisfied.
The new seasons conference cal-
endar begins with the Kashi-ophthacon 2004 at Varanasi andends with are our very own AnnualDOS meet on 3rd – 4th April, 2004.This issue brings out submissionguidelines for the annual conferenceand for the first time, we have madefacilities for online submission ofabstracts, which I am sure will makethe process much simpler.
Age Related Macular Degenera-tion (ARMD), the leading cause ofirreversible vision loss in industria-lised countries is also showing itsface in our setup. Results of tradi-tional treatment for wet ARMDwhich includes conventional laser,micronutrients are far from satisfac-tory. Alternate therapies like PDT,TTT, antiangiogenesis therapy and
submacular surgery are being triedout with variable success. In this is-sue we are focussing on importantclinical aspects of this disease and weare fortunate to have the opinion ofleading vitreoretinal surgeons in ourcountry.
With the end of this year oph-thalmic world has lost great Prof.Prem Prakash. A legend in his field,his sad demise has created a largevoid which can not be filled in manycenturies. I am thankful to Dr.Pradeep Sharma who has written aapt orbitury in respect of lateProfesser Prem Prakash.Thank you,
Dr. Jeewan S. TitiyalSecretary, DOS
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SN: What is ARMD and how do you diagnose it? (To RVA &CMS)
RVA: l Age related macular degeneration (ARMD) is a diseaseof the macular area, most often clinically apparent after 50 yearsof age. Early ARMD includes discrete yellow spots at themacula(drusen), hyperpigmentation of the RPE or sharply de-marcated areas of RPE depigmentation. Late ARMD includes geo-graphic atrophy of the RPE with visible underlying choroidal ves-sels, PED with or without neurosensory detachment, subretinal orsub-RPE neovascularization or fibroglial scar tissue, hemorrhageand exudates.
CMS : Age related macular degeneration is suspected when thereis a history of gradual or sudden loss of central vision in an elderlyindividual. Diagnosis is usually established by examination of themacula by slit lamp biomicroscopy with a 90D/78D non contactlens or Mainster Contact lens. Fluorescein angiography and some-times indocyanine green angiography are required before a treat-ment plan can be made.
SN: How do you define classic or occult CNVM? (To RVA &DT)
RVA: l The lesions are defined on the basis of fluorescein an-giography. Usually I decide on (a) Early frames i.e. early A-V phaseapproximately 40-50secs afterdye injection (b) Midphaseframes approximately 2-3 min-utes after and (c) Late framesof angiogram i.e. 5-6 minutesafter dye injection.l Following are the FFAcriteria of classifying CNVM:Ø CLASSIC CNVM –It isa well defined memberanewhich on fluoroscein angiog-
Age-related Macular Degeneration
raphy fills with dye in a lacy pattern during the very early phase ofdye transit, fluorescence brightly during peak dye transit and thenleaks into the subretinal space and around the CNVM within 1-2minutes. The fibrous tissue within the CNVM than stains with dyewith late hyperfluorescence(5-6 minutes).Ø OCCULT CNVM-It is a poorly defined memberane withcicatrisation along with and is of two types (i) Which has lessprecise features on the early frames with late leakage from unde-termined source or (ii) Fibrovascular PED which is a combinationof CNVM and PED. It manifests as a region of stippled or ill de-fined leakage in late phase into an overlying neurosensory retinaldetachment without distinct source focus identified on early frameof angiograms.
DT: The differentiation of a choroidal neovascular membrane(CNVM) into the classic and occult types is based on fluoresceinangiography. A classic subretinal neovascular membrane (SRNVMor CNVM) presents a fluorescein angiographic picture character-ized by early onset of hyperfluorsescence from the arterial phaseof the FA, during which a neovascular net may also be seen. Thislesion shows progressive increase in the intensity of thehyperfluorescence in the late phase of the FA, with a bluring of themargins of the lesion.
In contrast, an occult CNVM has three common presenta-tions. The first is a late leak-age from an unknown source.In these lesions, the earlyphase of the FA does not showany well defined lesion but bythe mid phase of the FA, anarea of increasinghyperfluoresence begins to getvisualized. The intensity of thehyperfluorescence and eventhe extent of the lesion in-
Age related macular degeneration (AMD) is one of theleading causes of bilateral irreversible severe visual loss inindividuals over 50 years of age due to formation of choroidalneovascularization (CNV) between retinal pigment epithelium(RPE) and Bruch’s membrane or subretinal space. Laser pho-
tocoagulation is considered as the preferred treatment mo-dality for extrafoveal and juxtafoveal classic CNV. However,because of the deleterious effects of the laser to the retina,
and also its limitations to treat only the extrafoveal and/or juxtafoveal CNV, clinicians have now shifted to various newtreatment options for subfoveal CNV lesions like photodynamic therapy(PDT), transpupillary thermotherapy(TTT), radio-therapy, interferon alpha-2, macular rotation and submacular excision of membrane, of these the most promising are TTTand PDT.
Dr. Sanjeev Nainiwal (SN) , from the Vitreo Retinal and Medical Ophthalmology Services at Dr. Rajendra PrasadCentre for Ophthalmic Sciences, AIIMS, New Delhi asked Dr. Rajvardhan Azad (RVA) , Professor in Vitreoretinal Unit at Dr.R P Centre for Ophthalmic Sciences; Dr. Tara Prasad Das (TPD) , Consultant in Retina Unit at L V Prasad Eye Institute,Hyderabad; Dr. Cyrus M. Shroff (CMS) , Consultant in Vitreoretina at Shroff Cheritable Eye Hospital, Daryaganj, New Delhiand Dr. Dinesh Talwar (DT) Senior Consultant Apollo Indraprastha Hospital, New Delhi & Director, Vitreo Retina & LaserServices, Centre for Sight, New Delhi, for their views on different aspects of this vast and interesting topic. Their replies aregiven in the text.
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Dr. Rajvardhan Azad Dr. Tara Prasad Das Dr. Cyrus M. Shroff Dr. Dinesh Talwar
DRY ARMD WET ARMD
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creases over time upto the late phase of the FA. In order to be ableto make a diagnosis of these lesions conclusively, it is mandatoryto take photographic frames during fluorescein angiography fromthe arterial phase upto at least 8 minutes after the fluoresceininjection.
The second presentation of an occult CNVM is that of afibrovascular pigment epithelial detachment, which presents withan irregular elevation of the RPF showing stippledhyperfluorescence within 1-2 minutes after fluorescein dye injec-tion, with persistant staining or leakage in the late phase framesof the fluorescein angiogiam.
The third common presentation of an occult CNVM is of aserous retinal pigment epithelial detachment, which presents clini-cally as a dark blister type of lesion with a ring halo around it. Onfluorescein angiography, this lesion shows hyperfluorescencewhich is relatively uniform and well defined and starts in the earlyphase of the FA. The hyperfluorescence become uniform andmore intense in the late phase of the angiogram but the marginscontinue to remain well defined.
SN: Why ARMD has become important in the present con-text? (To RVA & DT)RVA: ARMD is the most common cause of irreversible visualloss in the western world in individuals over 50 years age. 90% ofvisual loss in cases of ARMD is because of wet form of thedisease.According to Beaver dam eye study in USA 0.1%-0.42%of population between 55-64 have wet ARMD. End stage blindingARMD is found in about 1.7% of all individuals aged over 50 yearsand in 18% in those over 80 years. In a community based surveyconducted by our centre , 1% of individuals above the age of 50years were found to have ARMD(unpublished data).
DT: This question is extremely important for all of us. To answerit, is necessary to look at few demographic figures. According tothe latest census figures available, 13.1% of our population, com-prising 131 million people is over the age of 50 years; 2.6% of thepopulation (i.e. 26 million people) are over the age of 70 years and1.3% of the population is over the age of 80 years (i.e. 13 millionpeople). If we extrapolate the figures available, it is likely that eventoday we have 300,000 people who are blind due to Age RelatedMacular Degeneration, a figure which is not different from the totalprevalence of blindness due to ARMD in UK. Since the incidenceof both non exudative and exudative ARMD increases sharplybeyond the age of 70 years, an increase in life expectancy of ourpopulation, which is likely to follow improvements in the socioeco-nomic status of our population in the next decade, will result in amassive increase in the prevalence of this problem, as a majorcause of blindness in the community. The problem is likely to beaccentuated further by our success in efforts to ameliorate theavoidable and curable causes of blindness like Vitamin A defi-ciency and cataract.
SN: What are possible causes of visual loss in ARMD? (ToTPD & DT)
TPD: The likely causes of visual loss in ARMD are thinning andscarring of the retina as occurs in geographic atrophy and disci-form scars. Subfoveal bleed is the cause of severe visual loss insub foveal CNV. In some cases associated cystoid macular edemacontributes to visual loss.
DT: Causes of visual loss in ARMD includes damage / degen-
eration of the underlying retinal pigment epithelium in Dry ARMDwhile in Exudative ARMD, visual loss is a consequence of:(a) presence of exudation under the retina(b) presence of a membrane with / without development of
scar tissue causing distortion and damage of the photore-ceptors.
(c) Presence of subretinal blood, which again causes directdamage to the photoreceptors.
SN: What are the treatment options available for ARMD? (ToRVA & CMS)
RVA:l Argon/Krypton Laser photocoagulationl PDT (Photodynamic therapy)l TTT(Transpupillary therapy)l Submacular surgeryl Macular translocation surgeryl Trace metals and antioxidantsl Antiangiogenic therapyl Oral thalidomide and interferon alpha, gene therapy.l Use of electronic chip implants.
CMS: Laser photocoagulation for extrafoveal and minimallyjuxtafoveal lesions.
PDT and TTT for subfoveal and extremely juxtafoveal le-sions. Antiangiogenic drugs are also showing promise and thesemay be used in conjunction with PDT/TTT.
SN: What does your pre-laser work up include? (To RVA,CMS & TPD)
RVA: We at our centre, follow the following protocol for all ourpatients:w Best Corrected Visual acuity (Snellen and ETDRS)w IOP(Applnation)w Amsler grid (Scotoma score)w Contrast senstivityw Near Visionw Reading speedw Color fundus photographyw FFAw ICG angiography (wherever required)
CMS: Clinical examination including Amsler grid, Fundus fluo-rescein angiography(FFA), sometimes indocyanine green angiog-raphy (ICG) and optical coherence tomography (OCT). The cho-roidal neovascular membrane is mapped on a red-free/FFA phototo help in precise treatment.
TPD: My pre laser work-up includes Amsler Grid; ETDRS letteracuity, fundus photograph, combined FFA and ICGA, and OCT.
SN: For TTT, how do you decide your spot size and laserpower?
RVA: After measuring the Greatest linear diameter(GLD) on digitalfundus camera, I consider the followingw Add 1000 microns to GLD so that spot size should encompassthe entire lesionw Laser spot options available on Iridex diode laser are:0.8mm,1.2mm, 2mm, 3mm. & 5mm (new)w Power setting of 300-550 mw are good for Indian eyes.This is lesser compared to western eyes that have less pigmen-tation.
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A crude method to calculate laser power is to put a testburn in the periphery in inferonasal quadrant, find threshold andreduce the power by 10%. End point should be no visible reactionat the end of the treatment of the lesion.
CMS: Size of spot lesion diameter at least + 500 microns. If thelesion is larger than 3 mm more than one spot is used in a way thatoverlap is minimal. Always use test burn. If the lesion has signifi-cant fluid I use same power which produced minimal colour change.If the lesion has very minimal fluid or is pigmented, I reduce powerby 10%. I do not reduce power for classic choroidal neovascularmembranes.
TPD: Since I do not do TTT I can not answer this question.
DT: I do TTT in all patients who cannot afford PDT. I choose thespot size that covers the active CNVM completely in a single sit-ting. For determination of the laser power to be used, I carry outtest spots in the inferior quadrant of the retina just posterior to theequator, using 0.8 to 1.2 mm size spots. I determine the thresholdpower required for the test spot by incremental increase in thelaser power till a barely visible burn is obtained. I then calculatethe power of the actual treatment spot by using the formula :
(PT) Power Required For treatment = Diameter of treat-ment spot ´ Power required to create visible burn with test spot
Diameter of test spot
SN: Which vision assessment chart do you use and why?RVA: We use both ETDRS and Snellen visual acuity charts. Weprefer ETDRS chart because it is a universally accepted visualacuity notation form.visual acuity is expressed in a standard num-ber, which makes it easy to do statistical calculations as com-pared to snellen chart that is expressed in terms of fraction.It
gives absolute value depending on the num-ber of letters read in the chart and it is verysensitive to subtle changes in vision.
CMS: Snellen. Plan to start using ETDRScharts.
TPD: I use ETDRS vision chart at 4 and Imeter distance. I use the reduced Snellenchart for near vision.
DT: Nidek autochart projector, which pro-vide a modification of the Bailey-lovey charts(on which the ETDRS charts are based).These provide 3 or more letters per line forassessment of the visual acuity and have lineincrements similar to those of the ETDRS.
SN: According to you which type ofpatients should be treated with PDT andwhy?RVA: Patients with classic subfoveal orjuxtafoveal CNVM should be treated with PDTas a rule. However, patients with occultsubfoveal or juxtafoveal CNVM should beconsidered for PDT if cost of the procedure isnot a consideration.
CMS: Small classic, subfoveal choroidalneovascular membranes with good vision. They respond well andPDT is the safest treatment with the least chance of vision dropafter treatment.
TPD: Classic and predominantly classic CNVs respond well toPDT. The information is based on the TAP results.
DT: As I have mentioned previously, the ideal patient for PDT isone with a small (< 4 disc area) subfoveal CNVM, which is classi-cal. However I would treat all patients of subfoveal ExudativeARMD, who can afford the treatment by PDT except patients withlarge, non progressive occult CNVMs with good visual acuity (6/12 or better). My criteria of affordability is as follows :(a) Treatment being reimbursed by governmental / non gov-
ernmental agency or insurance.(b) Monthly income sufficient to provide funds for an average
of one treatment every four months or so.(c) Savings adequate to put aside a sum of Rs. 2.5 to 3.5 lacs,
without affecting the quality of life of the individual (finan-cially). In a patient, whose better eye has near normal vi-sual acuity, treatment of the worse eye with a baseline vi-sual acuity of 3/60 or worse should only be done in excep-tional circumstances where money is abosolutely no con-sideration and the patient is highly motivated even after hehas been explained that the treatment would not improvethe quality of life significantly. Treatment of the better eyewith exudative ARMD is indicated even if the baseline vi-sual acuity is less than 3/60, provided there is minimal scartissue in the lesion.
SN: What all precautions should be taken pre/post PDT?(To RVA, TPD & DT)
RVA: l PDT procedure is relatively contraindicated in patients
with severe liver disease, unstable heart disease or uncontrolledhypertension.The dye should not be administered if the patient isallergic to porphyrin,suffers from porphyria or has received anyphotosensitizing drug within the last two days.l Patients are advised not to expose any part of body tosunlight or yellow light for atleast four days to avoidskinburn.Patients either go home fully covered with clothes ormay be admitted in hospital for four days.Precautions to be fol-lowed at home are using only tubelight and preventing sunlightexposure by putting curtains at the windows and door.
TPD: The basic precaution following PDT is to avoid direct lightto the treatment eye (preferably the face) for 5-7 days inclusive ofthe day of treatment. Hence we request the patients to wear longsleeve dresses (or sari), socks, gloves, hat, and the dark glassesfor few days. I also suggest avoiding computer and TV for thesedays. A complete dark room should be avoided since this willdelay the drug excretion. I also request them to avoid any surgeryin the facial region (such as ear and dental) for a week.
DT: We explain to all patients who are about to undergo PDTthat :(a) They are not allowed exposure to direct sunlight for 5 days(b) They must stay indoors with curtains drawn in front of all
windows for 5 days(c) They are not allowed to expose themselves to incandes-
cent bulbs for 5 days(d) No hair dyes are permitted for 5 days(e) Watching TV is permitted.(f) They do not need to stay in darkness. Some degree of
fluorescent lighting is good for them and would help to in-activate the dye paster
(g) On their way from the hospital to their home, the patientsmust :i. Wear a full sleeve dress covering their arms and legs
completely.ii. Shoes and socks are needed to cover the feet, while
gloves/ socks may be used to cover the hands.iii. A scarf / cap is used to cover the head and faceiv. To be on the safe side, a shawl / bed sheet is used to
cover the body from head to toe in addition to the aboveprecautions.
v. Special goggles are provided to cover the eyes.(h) Patients need to avoid visits to their dentist / ophthalmolo-
gists for 5 days after the procedure and any emergencymedical consultation must be made only after informingthe treating doctor about the exposure to the photosensi-tive dye.
SN: What is your experience with laser photocoagulation,TTT & PDT?
RVA: w PDT is the treatment of choice for subfoveal/ juxtafovealclassic CNVMw For subfoveal occult CNVM, both PDT/TTT can be tried.
Argon Green laser photocoagulation is the treatment ofchoice for extrafoveal CNVM.
CMS: Laser – Excellent for extra-foveal lesions.–Disturbing scotomas in juxta foveal lesions.TTT – About 70% stabilise vision. Very few improve vision.PDT – Not enough experience to comment.
TPD: In my experience, laser photocoagulation is indicated forextrafoveal CNV and selected cases of juxta foveal CNV. I preferthe PDT for subfoveal and selected juxta foveal CNV.
DT: laser photocoagulation is an excellent treatment forExtrafoveal CNVMs, but can be risky in juxtafoveal CNVMs (dueto the risk of the run of phenomenon – whereby a laser spot effectincreases during the follow up period and results in loss of visualacuity following treatment.PDT works best in classical subfoveal or juxtafoveal CNVMs butis also effective in small occult lesions.
TTT also works but is more unpredictable that PDT. Forpatients with classical CNVM, there is no doubt that PDT is betterthan TTT, especially in patients in whom the initial visual acuity isvery good (6/12 or better) In Occult CNVMs, the choice is lessclear. Both the treatments are effective but PDT is a safer option.Overall, one can expect stabilization of vision in about 50 – 60 %of patients, improvement in 10 – 20 % and deterioration despitetreatment in about 20% of patients, with both PDT and TTT.
At present, there is no doubt that PDT is the treatment ofchoice for all patient of subfoveal CNV (where treatment is indi-cated) who can afford it. In patients who cannot afford PDT, TTTis a viable alternative in most circumstances.
SN: What is your criterion for success of the procedure?RVA: I take improvement from baseline ETDRS visual acuity orstabilization or reduction in size/intensity of hyperfluorescence inthe lesion on FFA as criterion of success, although some peopleconsider TAP study criterion with 3 lines/15 letters of visual losson ETDRS chart.
CMS: w Stabilization of visionw Reduction in exudationw Reduced fluorescein leakagew Decreased thickness on OCT
TPD: My criteria of success is closure of the CNV complex withmaintenance of central vision (Best corrected visual acuity ± 1 0letters in the ETDRS chat).
DT: For conventional laser procedures, success is defined ascomplete destruction of the CNVM.
For PDT, success is again defined as complete resolutionof the active CNVM.
For TTT however, stabilization of vision, with decrease inintensity and / or extent of the leakage may be considered to be asuccessful endpoint and no further treatment may be carried outonce this is achieved.
SN: When do you decide about retreatment?RVA: w We call the patients for followup every month and do theprelaser workup. We decide retreatment on FFA and visual acuityusually at 3 months followup.w It is considered if FFA shows evidence of leakage after12wks of initial therapy.w If there is loss of vision from baseline, retreatment is done.
CMS: Laser:- Any residual or recurrent choroidal neovascularmembrane which is treatable with laserw TTT :- Exudation not reduced or increased. Can use OCT.w Fluorescein leakage increased.
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w Increasing size of choroidal neovascular membrane.
TPD: Re-treatment is based on baseline VA, FAA/ICGA com-pared to the earlier visits and recent progression of the AMD. TheOCT is extremely useful to locate and quantify any associatedfluid.
DT: Retireatment following conventional laser photcoagulationis carried out if persistant CNVM is found on a FA done 2-3 weeksfollowing laser treatment, provided the lesion has not becomesubfoveal.
Retreatment following PDT is carried out at 3 months ifevidence of peristant neovascularization is found on FA done atthat time. Retreatment in these cases is not carried out only ifextensive scarring has occurred and vision has dropped mark-edly and if it is judged that no more benefit is likely from the treat-ment. Retreatment following TTT is carried out 3 months after theinitial treatment if FA done at that time reveals increase in size /intensity of the lesion.
SN: Role of dietary supplements and antioxidants in pre-vention or treatment of ARMD? (To RVA, CMS & TPD)
RVA: w AREDS STUDY-concludes that persons>55yrs with ex-tensive intermediate size drusens, at least one large drusen, noncentral geographical atrophy in one or both eyes or advancedARMD or loss of vision due to ARMD in one eye should be consid-ered for supplementation.w Recommends Vitamin C - 500mg ,Vitamin E - 400IU,b caro-tene - 15 mg, Zinc oxide - 80mg, Cupric oxide - 2 mg.w We usually prescribe Tab Antoxid 1 BD, Tab Zevit 1 ODand Tab Evion 1 OD continous for 3 months and then alternatemonthly. This includes all the nutrients in required amount asmentioned in AREDS study.
CMS: There is a role in high risk cases. We prescribe especiallyto those who have lost vision due to wet age related maculardegeneration in one eye or have large drusen in both eyes. Apositive family history also influences the decision. We like tofollow the AREDS recommendation and are careful to take historyof smoking.
TPD: The age related eye disease study (AREDS) has suggestedthat use of certain specific antioxidants, vitamins and mineralscould possibly prevent or delay the progression of AMD. TheAREDS cocktail include Vitamin C and E, beta-carotene, zinc andcopper. This combination alone is not available in India; mostcombinations include leutin and zeaxanthine.
While I use these antioxidants and mineral combinationscurrently we need several other ancillary laboratory and clinicalstudies to substantiate these recommendations.
SN: What is your experience with macular translocationsurgery in ARMD?
RVA: I have no personal experience. The role of macular trans-location is still not established as long term follow-up is not avail-able and can have complications like retinal detachment, recur-rent CNVM, refractive errors and inadequate displacement. Lim-ited macular translocation with chorioscleral outfolding has shownbetter results.
CMS: Submacular excision has been universally, disappointing
in AMD. Macular translocation probably has a role in selectedcases but complication rate in most surgeon's hands remainsunacceptably high.
TPD: It is so limited that I should not comment.
DT: I do not have any personal expexence with macular rota-tion surgery in ARMD but am not exthused by the reported resultsin literature so far.
SN: Few last words to say?RVA: I would like my friends to take cognizance of the followingpoints:
All patients above the age of 50 years who present to anophthalmologist with decrease in vision should be examined forARMD and if needed refer to a retinologist. Patients at risk i.e. whohave multiple drusens or RPE atrophy should be advised to havea closer follow up and provided with Amsler grid for any metamor-phopsia or scotoma and immediately report to a ophthalmologist.This becomes more significant for those patients who alreadyhave wet type ARMD in one eye. The treatment of ARMD by PDTor TTT should not be considered as panacea. It is not meant forall kinds of ARMD and the success of treatment should be consid-ered when there is stability in the vision , which was not hithertopossible some 5 years ago.
CMS: Challenging disease. The challenge is to find an effectivearmamentarium of treatments which is cost effective. The treat-ments of promise are PDT, TTT, Antiangiogenic factors. In thefuture could be retinal cells transplants, gene therapy or suchrefined electronic vision that it makes everything else redundant.The other important challenge is a greater awareness among allophthalmologists so that the disease can be picked up and treatedat the earliest possible stage.
TPD:Ø We still do not know the exact pathophysiology of AMD.
Whenever we do not know the disease properly we havemany treatment options. Recent researches on the retinalangiogenesis and role of the vascular endothelial growthfactor (VEGF) appear very promising for future therapy.
Ø In India we must also do a population based epidemiologystudy to estimate the burden of AMD related blindness.
Ø One must remember that despite treatment the AMD pa-tients are low sighted. They can be helped considerablywith low vision aids and other rehabilitation services.
DT: The varied thereapeutic approaches available in our arma-mentarium for management of patients with ARMD provide us ameans to save / preserve the vision of a large proportion of pa-tients with ARMD.
Today, a combination of prophytaxis with antioxidants forpatients at risk for development of advanced ARMD, conventionallaser photocoagulation for Extrafoveal CNVM, PDT for juxtafoveal/ subfoveal CNVM in patients who can afford it, TTT for juxtafoveal/ subfoveal CNVMs in patients who cannot afford PDT and macu-lar surgery for patients for bilateral macular disciform scars offersthe best approach for effective management of most patients withARMD. These therapies and many more under development pro-vide many rays of hope to those afflicted with this previously incur-able disorder.
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On August 15th 1998 theauthors (Amar Agarwal)performed the first sub 1mm cataract surgery by atechnique called PHA-CONIT (1,2). In this the cat-aract was removed througha 0.9-mm incision. The prob-lem with this technique wasto find an IOL, which wouldpass through such a smallincision. Then on October2nd 2001 the authors did thefirst case of a Phakonit Roll-able IOL. The lens used wasa special lens from Thinoptxcalled the Choice 1.0 IOL.This was the first RollableIOL, which was implantedafter a Phakoint procedure,and as it was a rolled IOL theauthors called it the Pha-konit Thinoptx Rollable IOL.
PrincipleThe problem in phacoe-
mulsification is that we arenot able to go below incisionof 1.9 mm. The reason is be-cause of the infusion sleeves.The infusion sleeve takes upa lot of space. The titaniumtip of the phaco handpiecehas a diameter of 0.9 mm.This is surrounded by theinfusion sleeve which allowsfluid to pass into the eye. Italso cools the handpiece tipso that a corneal burn doesnot occur (3).
The authors separated thephaco tip from the infusionsleeve. In other words, theinfusion sleeve was takenout. The tip was passed in-side the eye and as there wasno infusion sleeve presentthe size of the incision was0.9 mm. In the left hand andirrigating chopper was held
which had fluid passing in-side the eye. The left handwas in the same positionwhere the chopper is nor-mally held i.e.; the side portincision. The assistant injectsfluid (BSS) continuously atthe site of the incision to coolthe phaco tip. Thus the cata-ract is removed through a0.9 mm opening.
TerminologyThe name Phakonit has
been given because it showsphaco (PHAKO) being donewith a needle (N) openingvia an incision (I) and withthe phako tip (T).
PhakonitA specially designed 0.9
mm keratome, an irrigatingchopper, a straight blunt rodand a 150 standard phaco tipwithout an infusion sleeveform the main pre-requisitesof the surgery. Viscoelasticis injected with a 26G needlethrough the presumed siteof side port entry (Fig.1).This inflates the chamberand prevents its collapsewhen the chamber is enteredwith the keratome. Astraight rod is passedthrough this site to achieveakinesia and a clear cornealtemporal valve is made with0.9-mm keratome (Fig. 2). Acontinuous curvilinear Cap-sulorhexis is performed fol-lowed by hydrodissectionand checking the rotation ofnucleus.
After enlarging the sideport a 20 Gauge irrigatingchopper connected to the in-
fusion line of the phaco ma-chine is introduced with footpedal on position 1. Thephaco probe is connected tothe aspiration line and thephaco tip without an infu-sion sleeve is introducedthrough 0.9 mm incision.Using the phacotip withmoderate ultrasoundpower, the center of thenucleus is directly embed-ded starting from the supe-rior edge of rhexis with thephaco probe directed ob-liquely downwards towardsthe vitreous. The setting atthis stage is 50% phacopower, flow rate 24 ml/minand 110 mm Hg vacuum.When nearly half of the cen-ter of nucleus is embedded,the foot pedal is moved toposition 2 as it helps to holdthe nucleus is lifted a bit andwith the irrigating chopperin the left hand the nucleuschopped. This is done witha straight downward mo-tion from the inner edge ofthe rhexis to the center of thenucleus and then to the leftin the form of an inverted Lshape. Once the crack is cre-ated, the nucleus is split tillthe center. The nucleus isthen rotated 1800 andcracked again so that thenucleus is completely splitinto two halves.
The nucleus is then ro-tated 900 and embeddingdone in one half of thenucleus with the probe di-rected horizontally (Figure3). With the previously de-scribed technique, 3 pieshaped quadrants are cre-
ated in one half of thenucleus. Similarly 3 pie-shaped fragments are cre-ated in the other half of thenucleus. With a short burstof energy at pulse mode,each pie shaped fragment islifted and brought at thelevel of iris where it is fur-ther emulsified and aspi-rated sequentially in pulsemode. Thus the wholenucleus is removed. Note infigure 7 no corneal burns arepresent. Cortical wash-up isthe done with the bimanualirrigation aspiration tech-nique (Fig. 4).
Phakonit ThinoptxRollabar IOL
Thinoptx the companythat manufactures theselenses has patented technol-ogy that allows the manu-facture of lenses with plus orminus 30 dioptres of correc-tion on the thickness of 100microns. The Thinoptx tech-nology is not limited to ma-terial choice, but is achievedinstead of an evolutionaryoptic and unprecedentednano-scale manufacturingprocess. The lens is madefrom off-the-shelf hydro-philic material, which issimilar to several IOL mate-rials already on the market.The key to the Thinoptx lensis the optic design and nano-precision manufacturing.The basic advantage of thislens is that they are Ultra-Thin lenses. These lenses arecalled the Ultrachoice 1.0lenses.
Eye Research Centre 19,Cathedral Road,Chennai-600086 (India)
CURRENT PRACTICE
300January, 2004 DOS Times - Vol.9, No.7
ThinlensÔÔÔÔÔ OpticsThe drawing labeled
ThinlensÔ Optics (Figure 5)illustrates the optical charac-teristics of the ThinOptX'slens. The front surface is acurve that approximates aradius. The back curves is aseries of steps with concen-tric rings. The back surfacecan be concave, convex, orplano. The combination ofsteps with the front radiuscorrects for spherical aberra-tions. The convex and planoback designs can be used forpositive power lenses. Theconcave or meniscus backsurface is used for negativepowered lenses. In thedrawing labeled RefractiveLens lines intersecting thelens represent parallel light.The light is bent at the inter-section of the lens surface inaccordance with Snell's Law.When light strikes the lenssurface, the light is bent to-ward the central axis. All theparallel light rays enteringthe back of the lens come tofocus at approximately thesame point, therefore thelens is a Refractive Lens.
GlareIn the late 1970's lens
companies made a lens withan optic that was 5 by 6-mil-
limeters. The edge for a 20-diopter lens with a 0.250-millimeter haptic was 500-millimeters. The edge wastwice as thick as a standard6-millimeters lens. Reportsbegan of patients gettingglare and halos in low lightconditions. It is doubtful thepupil was opening to some-thing greater than 5-milli-meter. For light ot strike theedge of the lens with the lensin the posterior chamber, itseems the pupil would haveto be greater than 5-millime-ters.
Other AberrationsThickness causes a form
of aberration due to lightrays traveling longer in thethicker portion of the lens.The error is additive tospherical aberrations, but issmall if the lens manufac-
turer controls the thicknessof the lens or compensatesfor the differences in thick-ness when measuring thelens. The error is not asmuch from the thickness asthe fact that most lensbenches are calibrated usingthe back focal length of thelens. A correction factor forthickness is added to deter-mine the lens power. Theprocess can be very accurateif the differences in thick-ness of the lens are not sig-nificant or the lens bench iscalibrated between each lenspower. The bench should becalibrated even with thesame lens power if the lensthickness changes signifi-cantly.
The ThinLens™ is so thinthat the error goes away.With a central axis thicknessof 50-micron for a meniscus
lens and 300-micron for a bi-convex or plano optic, thereis little error in measuringthe lens due to thickness. Infact with the ThinLens™ onecan measure lens designedto the same power withoutadjusting the lens bench.The thinness is one of thereasons the ThinLens™ canbe manufactured in 1/8-di-opter increments.
Fresnel LensBy definition, the
ThinOptX™ lens is not aFresnel lens. The drawinglabeled Fresnel Lens isshown in Figure 7. As seenfrom the drawing (Figure 5),the lens has multiple focalpoints. This makes this stylelens Diffractive.
The normal lines on theback surface of the FresnelLens of not originate fromthe same point; therefore,the back surface of the lensfunctions as a series ofprisms. By selecting theangle the incoming lightrays make with the normalline of each prism, one canchoose the focal pattern ofthe resulting light. One suchapplication is the headlampof an automobile. The sec-ond surface of the Thin-Lens™ is designed to assistthe front surface in focusingthe light at a single point,
CURRENT PRACTICE
Fig. 3 : Phakonit continued. The nuclear pieces arechopped into smaller pie shaped fragments
Fig. 4 : Bimanual irrigation aspiration
Fig. 1 : A 26 Gauge Needle with viscoelastic mak-ing an entry in the area where the side port is. Thisis for entry of the irrigating chopper.
Fig. 2 : Clear corneal incision made with the keratome(0.9-mm). Note the left hand has a straight rod to sta-bilize the eye as the case is done without any anes-thesia. These instruments are made by katena (USA)
301January, 2004 DOS Times - Vol.9, No.7
which by definition is a Re-fractive lens.
Lens Insertion TechniqueThe lens is taken out form
the bottle. The lens is thenheld with a forceps. The lensis then placed in a bowl ofBSS solution that is approxi-mately body temperature.This makes the lens pliable.Once the lens is pliable it istaken with the gloved handholding it between the in-deed finger and the thumb.The lens is then rolled in arubbing motion. It is prefer-able to do this in the bowl ofBSS so that the lens remainsrolled well. It is better to dothis without gloves as therolling is much better.
The lens is then insertedthrough the incision care-fully (Figure 6). The tip of thehaptic should haves apointed shape, which willallow the lens to penetratethe corneal wound. One can
then move the lens into thecapsular bag (Figure 7). Theteardrop on the hapticshould point in a clockwisedirection. The smooth opticlenticular surface will be fac-ing posteriorly. The naturalwarmth of the eye causes thelens to open gradually. Vis-coelastic is then removed
with the Bimanualirrigation aspirationprobes. The tips ofthe footplates areextremely thinwhich allow thelens to be posi-tioned with thefootplates rolled tofit the eye.
SummaryFirst of all, we haveto remove the cata-ract through a sub 1mm incision. This ispossible with thePhakonit technol-ogy as cataracts canbe removedthrough that inci-sion. This was doneby us on August15th 1998. Nowcoming to the issueof the lens. When
we saw the lens we realizedthere were certain problemsin it. The lens had to berolled properly. When werolled the lens with thegloves the rolling was notgood, so we decided to rollit without gloves under theBSS. This gave us excellent
rolling. This can be im-proved by having an instru-ment that would roll thelens.
Now the second problemwhich we noticed in the lenswas the size of the lens. Thelength was all right by thebreadth of the lens was toobig to go through. Perhapswith an instrument whichrolls the lens it would be bet-ter but with the present sys-tems it was too large. If welook at a nonfoldable PhacoIOL the optic is just 5 mm. Ifwe look at the Accommodat-ing IOL, model AT-45, theoptic size is 4.5 mm. StuartCumming made this lens sothat it accommodates andthis can be possible onlywith a smaller optic lens.These patients do not havea glare problem. Keepingthis in mind, we cut the lensvertically on either side. Thisway the lens became smallerand easily maneuverable.The optic size reduced.When we rolled this lensand implanted it we couldachieve what we wanted.
Fig. 7 : Lens in the capsular bagFig. 8: Bimanual remoral of vicso-elastic, the IOL in the bag, full opened.
Fig. 9: Phakonit: No induced astigmation
Phaconit Thinoptx Rollable IOL
PRE-OP POST-OPDAY 30
302January, 2004 DOS Times - Vol.9, No.7
CURRENT PRACTICEtient having a glare andwhether the cut edges of thelens will produce any prob-lems to the patient. Whenwe saw the patient the nextday we noticed the patienthad no glare and the lens re-acted very well in the eye.This convinced us that thesolution was to have asmaller optic size lens withthe same length to solve thisproblem. If you will see thephotos you will notice theoptic size being smaller andthe cut edges of the lens.
Then we checked thepatient's topography andastigmatism. There is nopoint in having a lens gothrough a 1 mm incision andthen still have problems ofastigmatism. Phakonit is atougher surgery to performthan Phaco so the point is thesurgeon should be con-vinced that it make sense for
him to shift into a smallerincision. When we saw thepatient there was no astig-matism. In phaco with fold-able IOL we do get a bit ofastigmatism. Topographywas also done but we needto do more cases to docu-ment topographic changesin Phakonit compared toPhako (Figure 9).
Now coming to the futuremodifications of the lenswhich are required.1. We need to have a lens
the same length as whatis already present but thewidth being smaller.
2. We need to have an in-strument that will roll thelens
3. We need to have an injec-tor that will insert thelens. At present we areusing a forceps which isnot the right way as it cantear the lens. This injector
should be without a car-tridge as the lens shouldbe the cartridge also.
4. Alternatively, we shouldgive the surgeon a pre-rolled lens.
Now, coming to the future -1. The lens should be an ac-commodating type or mul-tifocal type IOL2. This way we have notonly minimized astigma-tism but also will solve theproblem of Presbyopia.
Reference1. Sunita Agarwal, Athiya
Agarwal, Mahipal S Sachdev,Keiki R Mehta, I Howard Fine,Amar Agarwal: Phacoemulsifi-cation, Laser Cataract Surgery &Foldable IOL's Second editionJaypee Brothers; 2000, Delhi, In-dia.
2. Benjamin F Boyd, SunitaAgarwal, Athiya Agarwal, AmarAgarwal: Lasik and BeyondLasik; Highlights of Ophthalmol-ogy; 2000, Panama.
3. Laura J Ronge: ClinicalUpdate; Five Ways to avoidPhaco Burns; February 1999
Where is my copy ofDOS Times?
Dear DOS members, anyone who could not receiveDOS Times from the month of January, 2004 onwards.
Please Contact: MR. SUPROTIK BANERJIM/s. Syntho Pharmaceuticals Pvt. Ltd.
31/16, 2nd Floor, Old Rajinder Nagar, New Delhi-60E-mail: [email protected]
Programme for DOS Monthly Clinical Meeting for January 2004
Venue: Lecture Threatre Complex, Behind New OPD Block, Safdarjung Hospital, (MVMC), New DelhiDate & Time : 31st January, 2004 (Saturday) at 2.30 P.M.
Case Presentation
1. Case-I ....................................................................................................... Dr. Munish 10 Mins.
2. Case-II ...................................................................................................... Dr. Seema Bajaj 10 Mins.
Clinical Talk
l Recent advances on role of Antioxidants in Ophthalmology ......... Dr. B.P. Guliani 20 Mins.
Mini Symposium: AstigmatismChairman : Dr. K.P.S. Malik,
Co-Chairman : Dr. A.K. Grover
1. Knowing Asigmatism and its Relationship withintraocular Surgery................................................................................ Dr. Ruchi Goel 10 Mins.
2. Plan to correct pre-op Astigmatism during Surgery ........................ Dr. A.K. Grover 10 Mins.
3. Correction methods for surgically induced Astigmatism ............... Dr. K.P.S. Malik 10 Mins.
Panel Discussions : 15 min.
303January, 2004 DOS Times - Vol.9, No.7
Rhegmatogenous retinaldetachment is the common-est surgical problem encoun-tered by a Vitreoretinal sur-geon. Last two decades havewitnessed, advances inVitreoretinal surgical tech-niques that have enabledanatomical success rates toclimb to 90% and better evenin situations like multiple,large and posterior breaks.The cornerstone of retinal de-tachment surgery howeverremains closure of all retinalbreaks, which may beachieved by scleral bucklingor internal tamponade withor without vitrectomy. Theaim of this article is to high-light various problems onemay encounter while per-forming a scleral bucklingprocedure, the practicalways to overcome them aswell as other problematicsituations that may be asso-ciated with retinal detach-ment e.g, myopia and hazymedia.
Problems during ScleralBuckling procedure1. Problems associatedwith anesthesia
These include compres-sion of globe by mask thatmay result in central retinalarterial occlusion; retro bul-bar hemorrhage; Globe per-
Problem Situations in RetinalDetachment SurgeryCyrus M. Shroff 1 MD, Ajay Aurora 2 MS
2. Shroff Charity Eye Hospital,Darya Ganj, New Delhi-2
foration; optic nerve damageand brain stem anesthesia.All these are uncommon torare. Of these the importantones include Retrobulbarhemorrhage and globe per-foration. Retrobulbar hemor-rhage, if severe, can lead toclosure of central retinal ar-tery. Hence, if one has de-cided to postpone surgery,an ophthalmoscopic exami-nation is mandatory. If CRAis occluded a paracentesiswill help. Globe perforationis rare (0.1%). The likely can-didates include myopic pa-tients and injection by indi-viduals not conversant withocular anatomy. Manage-ment is based on the compli-cations and may requirevitrectomy.
2. Problems during expo-sure & localization
Include scleral rupture orperforation, rectus musclerupture and vortex veindamage.
Scleral rupture most oftenoccurs in re-operations andusually happens below therectus muscles. It may beavoided by using a blunthook and dissecting undergood visibility. In the eventof its occurrence, it is impor-tant to remove all tractionfrom the globe and suture theruptured sclera. Followingthis it is necessary to exam-ine the retina and treat ac-cording to the complicationsthat may have developed.
Rectus muscle rupture isa rare complication and mayhappen in reoperations andpatients who are frail andold. The muscle may rupturefrom its tendon attachmentto the sclera or from its belly.It needs to be immediatelysutured with 6/0 vicryl.
Vortex vein damage usu-ally occurs in reoperationsand if muscle hook is takenbeyond the equator. If it oc-curs, it is necessary to cau-terize the vortex vein imme-diately. This may rarely leadto intraocular hemorrhage.
3. Problems due toVisualisation
Visualisation may be im-paired due to problems atvarious steps of surgery.These may include cornealopacification, pupillary con-striction, hyphema and mul-tiple bubbles after intraocu-lar gas injection.
Cornea may become hazyduring surgery due to epi-thelial edema that developsdue to poor handling, pro-longed surgery or raised in-traocular pressure. The lat-ter may result from tractionsutures and /or scleral de-pression. Prevention is best
and attention needs to begiven to all cases, particu-larly those that have AC IOLand aphakes with poor en-dothelial cell count due tovarious reasons. Cornealdrying may be prevented byfrequent instillation of salineor by placing methylcellu-lose on the cornea. If epithe-lial haze does develop thesurgery can be completedwith a good view after de-briding the corneal epithe-lium with cotton tipped ap-plicator, blunt side of a15#blade or a hockey knife.Following epithelial debri-dement the cornea needs tobe frequently wetted to pre-vent drying.
Pupillary constriction mayoccur due to: prolonged sur-gery, associated hypotony,intraocular gas injected in anaphakic eye or when com-bined with vitreous surgery.Pupillary constriction can beprevented by frequent instil-lation of long lasting cy-cloplegic agents likecyclopentolate or homatro-pine before surgery. Aphenylepherine-induced di-latation may be misleading.Hypotony can be preventedby intraocular injection ofsaline and having the bucklein place before SRF drainage.Pupillary constriction thatdevelops during surgerymay be circumvented by:
1 Intacameral injectionof preservative free adrena-line diluted to 1:10,000 con-centration.
REVIEW
The cornerstone of retinal detachmentsurgery however remains closure of allretinal breaks, which may be achievedby scleral buckling or internal tampon-
ade with or without vitrectomy
304January, 2004 DOS Times - Vol.9, No.7
2. Use of iris hooks3. Use of torpedo suture
(with 10/0 prolene) in aph-akic eyes
4. Anterior vitrectomy incase the pupil is bound by amembrane
5. Excising portions ofiris sphincter with vitreouscutter
Hyphema is a rare occur-rence in a standard bucklingprocedure. However it mayoccur in eyes with rubeosisiridis, previous uveitis andan iris fixated or AC IOL. Inthese cases it invariably re-sults from associated hy-potony. Hence all steps thatprevent hypotony are likelyto prevent its development.In case it occurs, pupil maybe cleared of blood by a bi-manual AC wash, mechani-cal egress by methylcelluloseor Healon, or a closed ante-rior vitrectomy.
Fish egg phenomenondue to intravitreal gas injec-tion can obstruct the viewhence gas should only beinjected once all major stepsof buckling procedure havebeen completed. It may beprevented by:
1. Using a dry syringeand needle
2. Rapid injection of gasbubble
3. Positioning the needletip in the center of the ex-panding gas bubble
In case it occurs, thebubbles may be coalesced bystriking an aphakic globe byflicking motion of cottontipped applicator, injectingadditional amount of gasand rarely by removing thepreviously injected gas andinjecting a fresh gas bubbleby a bimanual technique.
4. Problems related to Sur-
gical stepsThese include problems
related to retinopexy, pas-sage of scleral sutures, drain-age of subretinal fluid, place-ment of buckle and intraocu-lar gas injection.
Problems related toretinopexy (Cryotherapy,diathermy or laser photoco-agulation; Cryotherapy be-ing the commonest mode ofretinopexy) may be due to:
1. Inadequate or exces-sive treatment
2. Faulty location oftreatment
3. Retinal Pigment Epi-thelial cell dispersion
4 Retinal or choroidalhemorrhage
5. Scleral damage or rup-ture
6. Damage to vortexveins
7. Elevated IOPMost of these complica-
tions can be prevented or re-duced in severity by follow-ing the correct method. It ismandatory to correctly placethe tip of the cryo probeagainst the scleral surface atthe area of the break. Misin-terpreting the shaft as theprobe tip results in posteriorcryo resulting in treatment ofunintended areas. Retrea-tment can be avoided by per-forming cryo in a planned se-quential manner around thebreak. Doing cryo around thebreak and avoiding the baseof the break itself can reduceRPE cell dispersion. Largebreaks and multiple breaksare better lasered than cryo
treated as the excessive vi-able pigment cells that are re-leased may lead to pre-reti-nal membrane formationand recurrent retinal detach-ment. Removal of the cryoprobe before the ice ball hascompletely thawed can re-sult in retinal hemorrhage,choroidal hemorrhage andrarely scleral rupture, par-ticularly in myopes with thinsclera:
Problems related toscleral suture placement areextremely important. Theyinclude problems related toscleral bite of insufficientdepth or an excessively deepbite. Many of these compli-cations may be prevented byusing magnification (e.g., useof operating microscope) to
pass the scleral sutures.An insufficiently deep
scleral suture may cutthrough during surgery orlater when it may be respon-sible for buckle extrusionthat may result in an un-sightly bulge, recurrent in-fections and extraocularmuscle imbalance and evenpersistent or recurrent reti-nal detachment.
A deep scleral bite couldresult in scleral perforation.This happens in upto 5% ofall scleral buckles and usu-ally occurs in myopes and inareas where the sclera is thin.When retina underlying theperforation is detached itleads to inadvertent SRFdrainage and or pigment re-lease; if it occurs at an areawhere retina is attached it
can lead to intraocular haem-orrhage, retinal incarcera-tion, retinal break, drainageof liquid vitreous and incar-ceration/prolapse of vitre-ous. Following are variousproblem situations one mayget in:
1. Perforation occurswith anterior bite with un-derlying retina being de-tached: suture is temporarilyleft in place and retina exam-ined with indirect.a) If suture material is not
visible and there is no as-sociated retinal damage,suture is left in place andposterior bite completed.
b) If suture material is vis-ible, there is no associatedretinal damage and thereis adequate retinal sepa-ration, the suture is re-moved and fresh oneplaced.2. Perforation occurs
with anterior bite with un-derlying retina being at-tached. Suture is left in place,Indirect done to assess thedamage. If there is hemor-rhage local pressure is giventill the hemorrhage stops, ifthere is a retinal break cryois applied and the break sup-ported if possible. The sutureshould be cut flush with thesclera and left in place andanother bite taken more an-teriorly.
3. Perforation occurswith posterior bite over de-tached retina and indirectreveals no retinal damagethen another bite is taken2mm posterior and a widerbuckle placed.
4. Perforation occurswith posterior bite over at-tached retina and indirectreveals retinal damage thenthe suture material is cutflush with the sclera, cryo-
REVIEW
Hypotony can be prevented by intraocu-lar injection of saline and having thebuckle in place before SRF drainage
305January, 2004 DOS Times - Vol.9, No.7
therapy done and anotherbite is taken 2mm posteriorand a wider buckle placed.
Problems related tosubretinal fluid drainage
This step is the most dan-gerous step of buckling sur-gery since it is a blind step.Despite all precautions fol-lowing complications mayoccur:
1) Intraocular hemor-rhage: Usually minimal andstops with pressure at the siteof drainage. One should at-tempt to prevent the hemor-rhage from passing belowthe macula by appropriatepositioning of the head. If itstill happens one can leavesome SRF behind to allowpositioning after the surgery.Despite these efforts if hem-orrhage accumulates belowthe macula one could use gas(e.g., SF6) to displace theblood or Vitrectomy may berequired.
2) Retinal Incarceration:Occurs in 2-3% cases. Devel-ops immediately after drain-age starts and is recognizedby sudden stoppage of thedrainage. All traction shouldbe released at this stage andretina examined. It appearsas localised depression ofretina with radial folds. Itmay be avoided by prepar-ing small opening in thechoroid, and draining at adependent position. If thereis only retinal incarcerationwith no retinal break, it isonly supported with abuckle; if there is associatedretinal break cryotherapy orlaser with indirect ophthal-moscope is additionallydone.
3) Hypotony: is associ-ated with increased risk ofintraoperative hyphema and
choroidal effusion. If retinalbreaks are flat, BSS /Ringerlactate may be injectedthrough the pars plana andif the breaks are elevated gasis injected.
Problems related to ScleralBuckle Placement
May be associated withbuckle size and location. Aproper scleral buckle shouldsupport both the anteriorand posterior margin of thebreak. If this is not possiblewith the widest buckle a ra-dial plomb may be placed orVitrectomy with internaltamponade may be neces-sary.
Radial retinal folds:Scleral buckles that signifi-cantly reduce the circumfer-ence of the globe lead to pro-duction of radial retinalfolds. If one of these folds
communicates with the reti-nal break (fish mouth phe-nomenon) it can lead to pas-sage of SRF posteriorly, lead-ing to recurrent retinal de-tachment or persistence ofdetachment. Increasing theheight of the buckle will in-crease the problem. Hencescleral buckle height may bereduced and/or radialplomb added or anintravitreal injection of gasmade.
Increased intraocularpressure: Scleral bucklingreduces intraocular volumeand also leads to forwardmovement of lens iris dia-phragm leading to raisedIOP. This is particularly im-portant in elderly patients
with compromised ocularblood flow and those withreduced aqueous facility.IOP particularly rises incases where the SRF is notdrained. In cases with re-cently operated cataract thewound needs to be rein-forced by additional sutures.Raised IOP may compromiseretinal perfusion by blockingthe central retinal artery. Thiscomplication may beavoided by keeping a care-ful watch on the optic nervehead before the buckle su-tures are made final and per-manent.
Vortex Vein Damage:Most retinal breaks lie ante-rior to the extrascleral por-tion of the Vortex vein. If abuckle is wide or the Vortexvein has an abnormal loca-tion and the buckle needs tobe placed over a vortex vein
the scleral bite may be takenon either side of theintrascleral portion of thevortex vein; the bite may alsopass under the extrascleralportion of the vortex vein. Aportion of the scleral bucklemay also be cut at its poste-rior border over the area ofvortex vein to prevent com-pression of the Vortex vein.At times compression ofVortex vein is unavoidableand this does not seem tocause any untoward effectsbecause of the collateral cir-culation. If a vortex vein getsaccidentally damaged theextrascleral stump can becompressed and cauterized.However great care shouldbe taken to avoid such dam-
age.
Complications of VitreousInjection
Intravitreal injection offluid or gas through parsplana is required in varioussituations and may result incomplications. The injectionmay happen in the subretinalor supraciliary space, maycause damage to the crystal-line lens, may elevate IOP ormay reduce visibility by fishegg phenomenon. It is usu-ally done with a 30gaugeneedle through the parsplana. The needle tip shouldbe seen through the pupilwith bevel facing the sur-geon. When injecting gas oneshould attempt to injectwithin the bubble. In aphakic eye the direction ofthe needle tip should be to-wards the optic nerve whilein an aphakic eye it can bemore parallel to the irisplane.
Retinal Detachment asso-ciated with Myopia
Following problems maybe encountered in managingretinal detachments in myo-pic eyes:
1. Greater chances ofperforation while giving ablock (both peribulbar andretrobulbar block) in myopeswho have equatorial or pos-terior staphyloma. Authorsprefer to give general anes-thesia to patients whose axiallength is greater than28mm.If general anesthesiais contraindicated, subcon-junctival infiltration may bedone followed by direct in-jection into the muscle conewith a cannula under directvisualization.
2. Small peripheral bre-aks or central breaks may be
REVIEW
SRF drainage the most dangerousstep of buckling surgery since it is a
blind step
306January, 2004 DOS Times - Vol.9, No.7
Monthly Meetings CalendarFor The Year 2003-2004
27th July, 2003 (Sunday)Army Hospital
30th August, 2003 (Saturday)Sir Ganga Ram Hospital
27th September, 2003 (Saturday)Hindu Rao Hospital
19 October, 2003 (Sunday)DOS Midterm Conference
1st November, 2003 (Saturday)R.P. Centre for Ophthalmic Sciences
27th December, 2003 (Saturday)Venu Eye Hospital & Research Centre
31st January, 2004 (Saturday)Safdarjung Hospital
28th February, 2004 (Saturday)M.A.M.C. (GNEC)
27th March, 2004 (Saturday)Mohan Eye Institute
3-4th April, 2004 (Saturday & Sunday)Annual DOS Conference
Attention DOS MembersThe Hi-tech DOS Library has started functioning onGround Floor, Dr. R.P. Centre, Delhi Ophthalmic Sci-ences, AIIMS, New Delhi-110029 rom 12.00 Noon to9.00 P.M. on week days and 10.00 A.M. - 1.00 P.M. onSaturday, Sunday. The Library will remain closed onGazetted Holidays. Members are requested to utilisethe facilities available i.e. Computer, Video Viewing,Latest Books and Journals. We are planning to sub-scribe two journals. Member can give suggestion in thisregard.
Dr. Lalit VermaLibrary Officer, DOS
missed when the retina inthese areas is attached or hasa shallow detachment andretina thin with poor contrast
3. Cryoprophylaxis cau-ses excessive RPE dispersionthat may be a contributoryfactor for failure of detach-ment and excessive cryo maylead to Suprachoroidal hem-orrhage.
4. Thin myopic globesmay give way on applicationof excessive pressure and ex-plant sutures may be diffi-cult to take.
5. While taking explantsutures if one encountersthin areas, interrupted su-tures that go superficial tothe sclera at that site may betaken.
Hazy Media associatedwith Retinal Detachment
Good visibility is essentialfor successful surgical resultin a case of retinal detach-ment. Various situations thatmay lead to hazy mediaother than corneal pathologyand early cataractous lensinclude:
1. Uveitis with vitreoushaze
2. Posterior capsularopacification
3. Eyes with non-dilat-ing small pupil
4. Associated vitreoushemorrhage
Cases of uveitis with reti-nal detachment have agreater chance of developingproliferative Vitreoretino-pathy. These cases need tobe put on local and systemic
steroids preoperatively. Ascleral buckling proceduremay be attempted if the vis-ibility becomes reasonableotherwise Vitrectomy is abetter option. It is importantto use atropine eye dropspreoperatively and keep thepupil well dilated.
Posterior capsular opaci-fication can be treated withliberal Yag capulotomywithout destabilizing theIOL followed by bucklingprocedure if the visibilitypermits. Alternatively onecan do a membranectomywith a cutter and then treatthe case with buckle orVitrectomy on its merits.
The problem of anondilating pupil may beovercome by use of irishooks, sphincterotomy andby the use of small pupil in-direct for buckling proce-dure.
If the visibility is poor dueto an associated vitreoushemorrhage that does notpermit adequate visuali-sation for buckling proce-dure vitreous surgery is nec-essary.
Complications of retinalreattachment surgery arebest prevented by anticipa-tion. It’s important to be vigi-lant and be an “online”thinking surgeon. If a com-plication occurs on the tableor the retina does not behaveas expected one should beprepared to change the planincluding performing Vitre-ous surgery.
REVIEW
OBITUARY
Prof. Prem Prakash, who left for heavenlyabode at New Delhi. We pray for the peace
of the departed soul.
307January, 2004 DOS Times - Vol.9, No.7
Ultrasound Biomicros-copy (UBM) is a high reso-lution ultrasound techniquedeveloped by Pavlin, Sherarand Foster in Toronto in thelate 1980's. UBM is a high-frequency ultrasound tech-nology that allows imagingof structural details of theanterior ocular segment atnear microscopic resolutionin living patients. It providesexceptionally detailed two-dimensional gray-scale im-ages of the various anteriorsegment structures.
Principle· UBM uses a scan trans-ducer having a much higherfrequency. The transducerfrequency of conventionaldiagnostic ultrasound in-struments is in the range of7.5 to 10 MHz. In contrast,the transducer frequency ofthe UBM instrument is ap-proximately 50 MHz.· UBM provides muchhigher image resolution (ap-proximately 25-50 um of lat-eral and axial resolution)than does conventional B-scan ocular ultrasonogra-phy. The improved imagedresolution is attributable tothe higher transducer fre-quency of the UBM.· UBM is not able to imageas deeply into the eye as isconventional B-scan. This isbecause improved imageresolution comes at the ex-pense of reduced depth ofpenetration of the ultrasonicbeam (limited to approxi-mately 5 mm for a 50-MHzUBM instrument). The lim-ited depth of penetration is
Dr. Rajendra Prasad Centre forOphthalmic Sciences,New Delhi
also associated with asmaller angular field.
TechniqueThe examination is done
with the patient in the su-pine position, after local an-aesthetic has been applied tothe eye. A sufficient palpe-bral fissure must be presentto accommodate an eye cupwhich is used to create asmall water bath. Normally
1% or 2% methylcellulosesolution is used. The eye cupdoes cause some discomfort,limiting the utility of thistechnique in children andsome adults. Scanning isperformed with the sus-pended arm of the instru-ment held above the eye cupand with the ultrasoundtransducer oscillatingwithin the methylcellulosesolution Software within theinstrument is designed tostop the instrument if itcomes too close to the cor-nea, thus preventing cornealdamage.
Clinical Uses in Glaucoma1. Quantification of the An-terior chamber angle
With the UBM one candraw calipers and directly
measure the angle recessprecisely. This is a very ob-jective method which is notpossible with gonioscopy. Ithelps to determine the exactdegree of angle closure andassess whether a patient ispredisposed to angle clo-sure.
2. Determining the mecha-nism of primary glaucoma
Ultrasound biomicros-
copy is usually able to deter-mine the mechanism of el-evated intraocular pressure(angle closure versus openangle) by showing the rela-tionship between the pe-
ripheral iris and the trabecu-lar meshwork. In addition,imaging of the anterior seg-ment structures is possibleeven in eyes with cornealedema or corneal opacifica-tion that precludes gonio-scopic assessment.
In open-angle glaucoma,UBM can be used to mea-sure the anterior chamberangle in degrees, to assessthe configuration of the pe-ripheral iris, and to evaluatethe iris insertion in relationto the trabecular meshwork.One can see if there is ananterior insertion of the iris.In eyes with a narrow angle,UBM shows the extent ofangle closure, reveals thedepth of the anterior andposterior chambers, andidentifies pathologic pro-cesses pushing the lens andiris forward
Quantification of the angle
UBM is a high-frequency ultrasoundtechnology that allows imaging of
structural details of the anterior ocularsegment at near microscopic resolution
in living patients.
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308January, 2004 DOS Times - Vol.9, No.7
3. Determining the mecha-nism of secondary glaucoma
In the pigment dispersionsyndrome there is a classicalpicture on the UBM whichtypically reveals posteriorbowing of the peripheraliris. In plateau iris syndromeUBM usually reveals abnor-mally steep anterior angula-tion of the peripheral iris, in-sertion of the iris from theanterior ciliary body, andretroiridic projection of theciliary processes. In eyeswith peripheral anterior
synechiae, UBM can revealthe extent of iridocorneal ad-hesion even if the cornea ishazy or opaque. The UBMhas been able to differenti-ate between primary angleclosure and secondary angleclosure due to processessuch as lens swelling anddislocation, massive hemor-rhagic retinal detachment
pushing the lens and irisanteriorly, and multipleneuroepithelial cysts of theiridociliary sulcus.
4. Determining patency oflaser iridotomy
After Nd-YAG laseriridotomy for angle closure,UBM can show whether theiridotomy is partial thick-
ness or full thickness andwhether the plane of curva-ture of the peripheral iris haschanged compared with thepretreatment findings.
5. Determining functionalstatus of a filtering surgery
After trabeculectomyUBM can show whether thesclerostomy aperture ispatent or blocked internally,whether the peripheral iri-dectomy is open or blocked,and whether the filteringbleb is flat, shallow, or deep.
Subacute ACG (Pupillary Block) UBM of a case with Pigmentary Glaucoma AC IOL haptic induced Pseudophakic Glau-coma
YAG Iridotomy Patent fistula of a Trabeculectomy Ciliochoroidal effusion
Cyclodialysis Angle Closure caused by Ciliary body tumour
Ultrasound biomicroscopy is usuallyable to determine the mechanism of
elevated intraocular pressure
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309January, 2004 DOS Times - Vol.9, No.7
Post Traumatic Cyst causing angle closure Ciliary Body Blood Flow
After tube shunt surgery,UBM can show the positionof the tip of the tube andwhether its orifice is open orplugged.
6. Evaluation of post opera-tive complications aftertrabeculectomy
After any type of glau-coma filtering surgery, UBMcan be used to detect andevaluate the extent of post-operative complicationssuch as ciliochoroidal effu-sion and cyclodialysis. Inciliochoroidal effusion UBMshows the ciliary body to beedematous and separatedfrom the sclera by a sono-lucent collection of supracili-ary fluid. Many cilio-choroidal effusions that aretoo limited in extent to bedetectable by indirect oph-thalmoscopy and slit lampbiomicroscopy can be im-aged by UBM. In cyclodialy-sis UBM shows a well-de-fined separation betweenthe uveal tissue and thesclera in the region of thescleral spur.
7. Post Traumatic Glau-coma
After blunt oculartrauma, UBM can be used toevaluate iris-angle abnor-malities associated with and
possibly obscured byhyphema, including anglerecession, iridodialysis andcyclodialysis, and to illus-trate the presence and extentof blood clots. Angle reces-sion is characterized onUBM by posterior displace-ment of the point of attach-ment of the iris to the sclera.In the acute stage, the post-traumatic recess is usuallyfilled with blood.
8. Evaluation of cysts andtumours causing angle clo-sure
Cysts and solid tumors ofthe anterior segment can beimaged in great detail withUBM. This technology canbe used to determine the in-ternal character of a lesion(solid or cystic), to ascertainwhether the lesion involvesthe anterior ciliary body oris restricted to the iris, andto measure the full extent ofthe lesion. UBM can revealwhether the lesion involvesonly partial thickness or fullthickness of the stroma andcan thereby aid in surgicalplanning.
It allows measurement ofthe lesion's thickness anddetermination of the pres-ence or absence or intraocu-lar invasion It also confirmsthe presence, character, and
extent of ciliary body tumorsand often reveals the routeof access of the tumor to thesurface by way of a scleralemissary canal.9. Biometry of the AnteriorSegment
With the UBM one candetermine the corneal thick-ness, anterior chamberdepth, posterior chamberdepth, IOL thickness, scleralthickness. One cannot deter-
mine the lens thickness dueto the reduced depth of pen-etration.
10. Study of ciliary bodyblood flow
With the new UBM ma-chines one can study theblood flow in the cilary bodyand see the effect of variousmedications / surgery onthe ciliary circulation.
References:1. Pavlin CJ, Sherar BA, Foster
FS. Subsurface UltrasoundMicroscopic Imaging of theIntact Eye. Ophthalmology1990; 97: 244-250.
cornea - To facilitate - Film stars- Aphakia corneal - Armed forces- Keratoconus healing
Contact lens is the bestmethod of correction of re-fractive errors as it providesclear and sharp vision withminimal distortion in theform of size and shape of theimage. Contact lens practicein India is increasing everyday despite the popularityof refractive surgery likeLASIK. Every ophthalmicpractitioner needs to beaware about fitting andmanagement of contactlenses. Soft contact lens be-came popular in late 1970,since then there has beenmany fold advancement inthe technology of design andunderstanding of fitting phi-losophies.
The soft contact lens hasthe advantage of greatercomfort and shorter adapta-tion period. It is larger thanthe hard lens and covers theentire cornea and extends tothe sclera. The soft contactlens is usually hydrophilicand is made of HydroxyEthyl Meth Acrylate(HEMA) and its co-poly-mers. There is a considerablevariation in the oxygen per-meability of the lenses; thehigher the hydration of thelens, the greater the oxygenpermeability.
Varieties of soft contactlensesA. According to wearingschedule
1. Daily wear soft contactlens: These contact lensesare worn during workinghours and removed beforebedtime. They typically last6 months to 1 year depend-ing upon the maintenance of
Fitting of Soft Contact LensJeewan S. Titiyal MD, Ramkishor Sah B.Sc.(H) Ophth., Rajesh Sinha MD
the lens.2. Disposable soft contactlens: These are daily, weeklyand monthly disposablelenses.3. Extended wear soft con-tact lens: These are wornovernight for upto oneweek.
B. According to use1. Soft toric contact lens:
It corrects the astigmatic er-rors of the eye. In recent timeastigmatism is no longerbarrier to successful contactlens wears.
2. Bifocal soft contactlens: Hate the idea of read-ing glasses or bifocal eye-glasses? There are contactlenses that correct both dis-tance and near vision.
3. Monovision soft con-tact lens: With a mono vi-sion, You wear one contactlens with one power to cor-rect distance vision andother contact lens with one
power to correct near vision.The distant vision lens isusually worn in your domi-nant eye.
4. Color soft contact lens:Today’s color lenses lookgreat on light and dark eyes,whether you need visioncorrection or not. Make adramatic or subtle change.
5. UV- blocking soft con-tact lens: Block the uv-rays,a contact lens that screen outthe sun’s harmful rays mayguard against cataract andmacular degeneration.
6. Special effect of softcontact lens: There is not justfor Halloween any more,Just for Fun, try being a Cat,Alien or Zombie.
7. Therapeutic soft con-tact lens: These lenses aremost commonly used to re-lieve pain, promote healing,provide mechanical protec-tion and support duringhealing. Sometimes they canalso be used as a means of
drug delivery.In the present chapter, we
will be discussing about thefitting philosophy of routinesoft contact lens for opticaluse only.
The Basic guidelines forfitting soft contact lensØ The soft lenses are usu-
ally fitted larger than thediameter of the corneaand the diameter rangesfrom 13.00 to 15.00mm(commonly 13.50 –14.50mm).
Ø A smaller eye requiressmaller diameter andconsequently steeperbase curve.
Ø There should be a 3-pointtouch fitting i.e. one at thecorneal apex and two atperiphery.
Ø There should be an ad-equate movement of 0.2 –1.0 mm of the contact lenswith each blink. Whilemany texts and fittingguides still refer to anoptimally fitting soft lensas being 1.0mm, the ac-tual post blink movementusually measures 0.2mmto 0.4 mm.
Ø Soft contact lenses aregenerally fitted flatter
Dr. R. P. Centre for OphthalmicSciences, AIIMS,Ansari Nagar, New Delhi.
Patients should have realistic expecta-tions from contact lens. There is false
belief in many individuals that contactlens wear arrests or eliminates the re-
fractive error
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311January, 2004 DOS Times - Vol.9, No.7
belief in many individu-als that contact lens weararrests or eliminates therefractive error.
Fitting ProceduresStep 1. Patient’s selection
The patient selection isbased on general health,ocular health, occupation,motivation, expectation ofthe patient and personalocular hygiene of the pa-tient.
The patient with the bestprognosis for successful fitting
is one who fulfills the follow-ing criteria:i. Refractive error >+
0.50DS, including Aph-akia.
ii. Low astigmatism < + 0.75DC
iii.Regular cornea (no anyscarring or/ distortion ofcorneal mires)
A. Indications: There aremany patients for whomcontact lenses are not merelya matter of cosmetic choice,but the best means of pro-viding a satisfactory visualcorrection (Table 1).B. Contraindications: Thereare great many factors,which may be considered ascontraindications (Table 2).
Step 2. Pre-fitting Examina-tion
This includes measure-ment of uncorrected andbest corrected visual acuity,
than “K” by about 2.00 –3.00D (approximately 0.4to 0.8 mm), dependingupon the diameter of thelens.
Ø If the ratio of spherical :cylindrical power > 4 : 1,it is appropriate to fit rou-tine spherical soft contactlens. If the ratio is less,toric contact lens is indi-cated.
Ø Power is finalized byover-refraction.
Ø The lower the water con-tent of the lens, the moredurable the lens. Thehigher the water content,the more fragile the lens.
Table 2: Contraindications of contact lens
Visual Cosmetic Medical Systemic conditions On Drugs Like Occupational Others
- If needed - Where - Chronic allergies - Diabetes - Topical drugs - Exposure to - Noncompliantonly for spectacles (Conjunctivitis) - Thyroid eye disease (Antiglaucoma dust, fumes patientsnear vision hide facial - Recurrent corneal - Pregnancy & Steroids) & chemical - Unmotivated
Ø The lower the water con-tent of the lens, the lesserthe build up of precipi-tates and protein depos-its. The higher the watercontent, the more the lensdeposits.
Ø The thinner the lens, thegreater the oxygen trans-mission to the cornea.
Ø Visual acuity should bebetter or as good as withspectacles.
Ø High plus & high minuslenses are fitted 0.5 mmlarger than low powers.
Ø Patients should have re-alistic expectations fromcontact lens. There is false
312January, 2004 DOS Times - Vol.9, No.7
cycloplegics refrac-tion, keratometry,videokeratographyand a detailed slitlamp biomicroscopyto rule out presence ofany structural andfunctional lid abnor-mality, tear film statusby schirmer andbreak-up time, con-junctival status especiallytarsal conjunctiva, cornealsurface, thickness and en-dothelial status, horizontalvisible iris diameter, ante-
rior chamber & lens statuspupillary size (Optic zone =pupil size + 2.0 mm) andshape by transparent scaleor pupillometer.
Step3. Basic Fitting Method1. Keratometry: Record the“K” readings and convert tomillimeters. (Table 3)2. Spherical power: To de-termine the required spheri-cal power, change the pre-scription to minus cylinderform and use the sphericalequivalent of the cylinder ifthe cylinder is greater than0.50D. Add this to thesphere to determine the ini-tial lens power. For example,if the spectacal prescriptionis - 6.00DS/ - 1.00DC X 900,
add ½ of cylinder (-0.50D) tothe sphere, so that power is-6.50DS. Compensate thevertex distance by VertexConversion (Table 4); so that
–6.50DS at spectacle plane(12mm) becomes – 6.00DS atthe corneal plane. The thicksoft contact lens alwayscompensates for a cylindri-cal power of – 0.50 to -0.75DC.3. Horizontal visible iris di-ameter (HVID): Measure theHVID in millimeters by cali-pers. The initial lens diam-eter to be selected should be0.2 to 0.5mm larger than theHVID.a. If the HVID < 11.50mm -
Lens diameter = 13.50mmb. If the HVID > 11.50mm –
Lens diameter = 14.50mm4. Select lens thickness:These are the following cri-
teria shown at timeof determination oflens thickness (Table5).5. Trial lens: If us-ing a trial set, selecta suitable trial lenswith a base curve of0.4 to 0.6mm (2.00 to3.00D) flatter thanthe flattest “K” in thesmaller diameter
lenses (12 to 13mm) and0.6 to 1mm (3.00 to 5.00D)flatter in the large diameterlenses (14 to 15mm).
Step 4. Lens placement onthe eyes:
Place an appropriate trialcontact lens and wait for 15-20 minutes for an equilibra-tion. The equilibration timemay depend on water con-tent of the lens. High watercontent lenses take longer tosettle because the volume ofwater is greater necessitat-ing a longer equilibrationtime.
Power range Lens series Rationales
- 0.50 to - 2.00Ds U or B Better handling
- 2.25 to - 5.50Ds U or O Balance betweenphysiology
- 5.50 to - 9.00Ds O or U Optimum oxygentransmissibility
- 9.50 to -20.00Ds HO Optimum oxygentransmissibility
Table 5: Different Power, Lens series & thickness of Lenses
The Central thickness:B - Series = 0.12mm U – Series = 0.07mmHO Series = 0.035mm Optima (38) = 0.06mm.
Table 4: Use the vertex conversion table "Average 12mm vertexdistance" For Minus Powers read Left to Right & Plus Powers read Right to Left:
General - No bulbar - Buckling of lens - Irritation of limbal orconjunctival edge conjunctival vesselscompression - Lens falling out of - Scleral indentation
the eye often seen after lensremoval
- More negative powerrequired than actualpower due toformation of plusliquid lens
Step 6. Over-refractionPerform an Over-refrac-
tion on a properly fitted lens.Refraction is done throughthe trial lens and power is fi-nalized as detailed earlier.
Step 7. Lens dispensingThe trial lens and refrac-
tion gives the base-curve,power, over-all diameter,optic zone, peripheral curveradius, width and thickness.
Step 8. Follow up carea. Visual acuity (VA)
with contact lens is recordedat each follow-up visit.
b. If the vision is lessthan previously recordedVA, then refraction shouldbe done through the lens(over-refraction).
c. Recheck the lens fit.d. Examination of the
eye and contact lens.e. Orthoptic check-up
should be performed in allthe myopes as there is animbalance of convergenceand accommodation whenone switches over fromspectacles to contact lens.
f. Indirect ophthalmos-copy should be performedin patients with high myo-pia as they are predisposedto retinal problems.
Suggested Reading:1. Contact Lenses: Anthony J.
Phillips, Janet Stone. A textbook for practitioner and Stu-dent (Third Edition)
2. Harold A Stein, Bernard J.Slatt, Raymond M. Stein: Fit-ting guide for Rigid and SoftContact Lenses.
4. Edward S. Bannet, VanitaAllee Henery: ClinicalMannual of Contact Lenses(Third Edition).
Step 5. Evaluation of thelens fit
Evaluate the fit of the lensaccording to the normal lensfit criteria.
According to the first fittheory
Fit smallest and thinnestlens which will provide:- Full corneal coverage/
Centration/Adequatemovement/Comfor t(Table 6)
Corrective measures for im-proper fitFlat fitØ Select a steeper base
curveØ Select a large total diam-
eter
Ø Use a lower water contentmaterial
Ø Use a different lens thick-ness
Steep fitØ Select a flatter base curveØ Select a smaller total di-
ameterØ Use a higher water con-
tent materialØ Use a different lens thick-
nessThe additional criteria
for best fit assessment: Anideally fitted lens should bewell centered, comfortableand must provide crisp vi-sion, proper corneal cover-age and adequate oxygensupply to the cornea.
porally with finger so that itis only one third on corneaand two thirds on sclera andits return is observed. Easydisplacement and easy re-turn to the cornea indicatesan ideal fit.
4. Lens edge liftDisplace the lens by
pushing the lower edge up-ward with the help of thelower lid and observe theedge lift at 6 o’clock. This isa guide about the fit.
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316January, 2004 DOS Times - Vol.9, No.7
Trouble free contact lenswearing patients are thekeys to increasing popular-ity of contact lens practicebase. There are however, notrouble free contact lenses orpatients. A smarter physi-cian adopts strategies to ad-vice his patients on how tohalt contact lens complica-tions before they start. Thereare a number of ways to clas-sify contact lens relatedcomplications. Generally,significant ocular complica-tions can be segregated intohypoxic, infectious, me-chanical, immunological orosmotic changes induced inthe eye from contact lenswear. While there is overlapamong the various catego-ries, the primary inciting fac-tor should be identified inorder to most appropriatelytreat the condition. This ar-ticle will focus on describingthe contemporary views oncommon contact lens relatedcomplications and how toavoid and handle them inusual clinical practice.
1. Hypoxic Complica-tions: Contact lens wear re-duces the amount of oxygento the cornea, especially un-der closed eye conditions.The oxygen required by thecornea for essential metabo-lism is obtained by diffusionfrom the air when the eye is
Contact Lenses Complicationsand their ManagementJagjit S. Saini MD, FIACLE
open, and from the tarsalconjunctiva when the eye isclosed. There are significantvariations in demand foroxygen among individuals.A partial pressure of 75 mmHg for oxygen is consideredadequate for healthy cornea.Numerous factors affect sus-ceptibility of cornea for hy-poxic damage, which in-clude previous ocular surgi-cal procedures. Eyes withprevious surgery such asaphakia or refractive proce-dures demonstrate poorerphysiological reserves to re-spond to additional meta-bolic insults of contact lenswear and need special con-siderations. The type of lensmaterial, lens thickness andlens design significantly in-fluences availability of oxy-gen to cornea. Complica-tions can result if contactlenses result in inadequatecorneal oxygenation giventhe patient’s physiologicaldemands and desired wear-ing schedule. Critical oxy-gen levels necessary to avoidcorneal edema in normaleyes under daily wear openeye contact lens use needsoxygen transmissibility inexcess of 24.1 x 10-9 Barrer/cm. Under closed eye ex-tended wear contact lensuse, lenses need to havehigher than 87 x 10-9 Barrer/cm oxygen transmissibility.Several current daily wearcontact lens materials anddesigns exceed the requiredoxygen transmissibility. Sili-
con-hydrogels lenses haveoxygen transmissibilityabove 100 and could be em-ployed on extended wearbasis in selected patients.Patients who wear lensesnot providing enough oxy-gen to the cornea risk devel-oping hypoxia. Commoncomplications related to hy-poxia include epithelial andstromal edema, increasedbacterial adherence to epi-thelial cells, decreased epi-thelial cell regeneration,compromised epithelialjunction integrity, micro-cysts and vacuoles, endothe-lial polymegathism and blebformation and corneal vas-cularization. Hypoxia re-lated problems would occurmore often in eyes withhigher oxygen demand orlow abilities to physiologi-cally compensate for meta-bolic insult. Acute hypoxiafrom over wear of contactlens is a frequent problemthat may manifest in mildasthenopia symptoms toacute pain and redness inthe eye.
Fortunately, most of theseacute complications can bemanaged rather easily bychanging lens materials.
It is important for thepractitioner to obtain fromthe manufacturer informa-tion of the oxygen transmis-sibility of the contact lens tomake informed decision.Neglecting hypoxia relatedproblems predisposes eye tomore serious complications
of infection.2. Infectious Complica-
tions: There is a spectrum ofinflammatory adverse reac-tions from contact lens wear.Many of these inflammatoryepisodes cause similarsymptoms of pain, redness,photophobia, puffiness oflids and discharge at lidmargins. Differentiatingearly microbial keratitisfrom sterile marginal infil-trates, an immunologic re-sponse, represents one of thegreatest diagnostic dilem-mas, and errors in treatmentand management can lead topotentially sight-threaten-ing consequences. There isclear information now thatcontact lenses worn on ex-tended wear basis have ahigher incidence of contactrelated infectious episodes.Although several factorsmay contribute, hypoxia,poor contact lens hygiene,and diseased state of the cor-nea are prominent.
Infectious keratitis (IK) ischaracterized by excavationof epithelium and corneastroma with infiltration andnecrosis. There is often ac-companying anterior cham-ber reaction and decreasedvision. While all types ofkeratitis can present in con-tact lens wearers, two maintypes of ulcerative keratitisare more frequently ob-served in contact lens users.These are bacterial keratitisand Acanthamoeba keratitis.Both can have significantvisual morbidity. Althoughother types of keratitis (vi-ral, herpetic fungal, para-sitic, etc.) can occur withcontact lens wear, the fre-quency with which thesetypes occur is generally notdifferent between contact
Professor of Ophthalmology,Post Graduate Institute of MedicalEducation and Research,Chandigarh, India.
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317January, 2004 DOS Times - Vol.9, No.7
lens wearers and non-con-tact lens wearers. While in-fectious corneal ulcer, is aninfrequent event, sources formicrobial contamination putall contact lens wearers atrisk. Common sources ofcontamination include theenvironment, the wearer’shands, the eye and ocularadnexa, a contaminated lensor lens case and contami-nated solutions.
Contact lens induced pe-ripheral ulcers (CLPU)(Fig.1)are characterized byfocal excavation of epithe-lium only. Although thereare infiltrates in the superfi-cial stroma, there is no de-monstrable necrosis or exca-vation extending to stroma.It is believed that toxins re-leased from gram positiveorganisms such as staphaureus colonizing on thelens itself may be causingCLPU.
Contact lens inducedacute red eye (CLARE) (Fig.2) manifests with focal ordiffuse peripheral cornea in-filtrates without disruptionof cornea epithelium. Thelaboratory evidence sug-gests that endotoxins re-leased from gram negativeorganisms on the contactlens are responsible forCLARE. The symptoms inCLARE are milder.
Any inflammatory epi-sode involving cornea is sus-pected to harbor infectiousorganisms on the cornea andcontact lens. Contact lenswear is discontinued for aslong inflammation persists.Biomicroscopic evaluationwill usually demonstratecharacteristic features. It isimportant that such lesionsare carefully recorded forsize, depth, and location.
Ulcers must have smear andbasic culture tests per-formed. Appropriate fre-quent topical antibiotics(author’s choice fluoroquin-olones) generally suffice. Itis however, very essential tomonitor and document heal-ing and follow usual proto-col to investigate in depth ifhealing does not progress.
Eyes manifesting CLPUor CLARE also need cessa-tion of lens wear and docu-mentation of cornea infil-trates. Most ophthalmolo-gists will administer pro-phylactic antibiotics as wellalthough in compliant pa-tients non-steroidal anti-in-flammatory drops andmonitoring may be enough.It is not useful to rush to ad-minister antibiotics in non-ulcerative cornea lesions.Every patient however,needs to be told clearly theneed for close monitoringand the dangers of neglect.Patients adjudged to be laxare not fit for using contactlenses. Usually, lenses insuch patients have featuresof spoilage. It is importantthat patients understandthat contact lens care solu-tions do not sterilize but re-sult in limited disinfection.When contact lens relatedinfectious episode has oc-curred, it is prudent to dis-card the spoiled lens, changelens case, and the bottle ofcare solution. Stringy pa-tients who may want to usethe lens a little longer mustbe warned to report any red-ness immediately.
3. Allergic and toxicityComplications: Althoughcontact lens materials arebiologically inert, an inflam-matory response may beprovoked in the cornea from
accumulation of debris un-der the lens or preservativessuch as thimerosal in contactlens care solutions. Toxic ef-fects on cornea from contactlens care products such asbenzalkonium chloride,alkyl triethanol ammoniumchloride, chlorhexidine glu-conate and disodiumedetate are known.
Superior limbic kerato-conjunctivitis is character-ized by symptoms of red-ness, irritation and tearing ofsudden onset in patientswho have worn lenses forsome time. The superior partof the cornea demonstratessuperficial vascularisationand epithelium haze. Thereis congestion of neighboringbulbar conjunctiva.
Giant Papillary Conjunc-tivitis may occur with anytype of contact lens, ocularprostheses, sutures, sclerabuckles or adhesives. Thesymptoms include de-creased lens tolerance, in-creased lens movement, in-creased mucus, blurred vi-sion and ocular itching. Ex-amination of the superiortarsal conjunctiva will revealtarsal injection, visible lossof the vascular pattern andpapules greater than 0.3 mm(Fig. 3). In the more severecases, the bulbar conjunctivamay be involved and theremay be a superficial punc-tate keratopathy. In addi-tion, apical staining of thepapules with fluoresceinmay be noted. Almost all pa-tients report significant coat-ing of the contact lens. Theincidence of GPC is higherwith soft lenses than withrigid lenses. The symptomsof GPC appear to be moresevere with soft lenses thanwith rigid lenses. GPC is
more common in atopic in-dividuals. This conditionalso appears to peak withthe height of the allergy sea-son. GPC is thought to be animmunologically mediatedcondition. Trauma is also afactor in the pathophysiol-ogy of GPC. Neutrophilchemotactic factor has beenfound in high concentrationsin the tears of GPC patients.As the antigen-coated con-tact lens traumatizes the tar-sal conjunctiva, the ocularimmune system releases in-flammatory mediators,which leads to the attractionof inflammatory cells suchas neutrophils, basophils,eosinophils and mast cells.These cells react with immu-noglobulins to cause the re-lease of vasoactive aminesthat are responsible for thesigns and symptoms of GPC.While the introduction offrequent replacement con-tact lenses has helped tomanage patient with GPC,this condition still occurwith frequent replacementlenses. The majority of pa-tients who develop GPC areon a four-week or greaterlens replacement schedule.
As with non-contact lenswearers, avoidance of the al-lergen is the first defense. Insome atopic patients, dis-continuance of lens wear orreduction of wearing timeduring the allergy seasonmay be warranted.
The availability of fre-quent replacement lenseshas expanded the optionsfor these patients. Switchinga patient to a more frequentreplacement schedule, in-cluding daily disposablecontact lenses, may improvecomfort. A more frequent re-placement schedule leads to
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318January, 2004 DOS Times - Vol.9, No.7
reduced lens coating and adecreased antigen load.Medical management, withantihistamines, mast cell sta-bilizers, or combinationproducts may also be effec-tive, though steroids shouldbe avoided for contact lenswearers. The use of mast-cellstabilizers or a combinationmast-cell stabilizer/ antihis-tamine may enable patientswith ocular allergies to weartheir contact lenses duringthe allergy season. The se-verity of signs and symp-toms is a reasonable bench-mark in the choice of treat-ment for contact lens relatedGPC. Patients with mildsigns and symptoms, shoulddiscontinue lens wear forone to two weeks. Considerchanging the lens replace-ment cycle for these patientsto about four-weeks, andmonitor the patient everythree months. Moderate lev-els of GPC will call for a two-to four-week discontinuanceof lens wear, to allow anyapical staining or superficialpunctate keratitis to resolve.These patients will benefitfrom a disposable contactlens. For severe cases, dis-continue lens wear for a
minimum of four weeks, oruntil the tarsal inflammationresolves. The papillary reac-tion will not abate duringthis period. These patientsshould be switched into adisposable lens fitting re-gime and followed everytwo to three months. If GPCrecurs, contact lens wearshould be discontinued un-til the signs of inflammationhave resolved. The patientshould be prescribed a mast-cell stabilizer or a mast-cellstabilizer/antihistaminecombination product for oneto three months. The drugcan then be slowly tapereddepending on the clinical re-sponse. Rarely, patients mayagree to accept rigid gas per-meable lens instead of theoffending soft contact lens.
4. Mechanical Compli-cations: Mechanical compli-cations can range from sub-clinical to visually signifi-cant. All lenses can produceeffects ranging from micro-trauma to full-thicknessabrasions, which put thecontact lens wearer at agreater risk for infectiouscorneal ulcers. Other typesof mechanical complicationsinclude corneal warpage,
which is readily evidentwith corneal topography.All contact lenses, soft in-cluded, commonly producemild corneal warpage,which may only be evidentwith corneal topography.No treatment is required formild warpage unless it issignificant enough to pro-duce spectacle blur or resultin unstable vision followingcontact lens removal. In pa-tients interested in refractivesurgery, it is imperative thatlens wear discontinued un-til corneal warpage is re-solved and serial topogra-phy is stable in order to re-duce the risk of corneal ecta-sia following refractive sur-gery.
Superior epithelial arcu-ate line (SEAL) manifests asarc like grayish white epi-thelial lesion with heapededges in the periphery ofsuperior cornea close to lim-bus. SEAL is believed to re-sult from mechanical dam-age to cornea.
Physical deposits fre-quently are observed oncontact lenses (Fig. 4). Thesedeposits predispose the eyeto several complications thatinclude infections and me-chanical irritation. Rarely,foreign bodies may betrapped under the lens andcause mechanical damage tocornea. Although depositson the lens and foreign bod-ies embedded in the lensmay be reduced after soak-ing in contact lens care solu-tion and mechanical rub-bing, they never really dis-appear. It is prudent to ad-vice change of lens when de-posits are visible on the lens.
5. Osmotic Complica-tions: Osmotic complica-tions result from changes in
the tonicity of the tear film,such as that which occursfollowing epiphora (hypoto-nicity) or in dry eyes (hyper-tonicity). Both hypotonicand hypertonic situationscan alter the fit of a soft con-tact lens, usually creating atight lens situation, leadingto a continuing cycle of fur-ther compromise. A changein tear pH and relative de-hydration results in tightlens syndrome because ofaltered lens structure andlens fit. Acute pain, redness,and blurred vision typicallyoccur 48-72 hours after re-moval of lens. Remedies in-clude refitting the lens asnecessary and treating theunderlying cause of the os-motic complication (pre-scribing lubricants, insertingpunctal plugs, etc.).
What to do When Compli-cations Occur:
Familiarity with symp-toms and treatment of con-tact lens complications helpsin providing efficient care tothe patient. It is important tofollow a consistent policy onwork up of these patients.
a. A thorough interviewis required in every patient.It is not enough to advicebased on symptoms elicitedthrough a friend or interme-diary. The chief complaintelicited will direct further in-quiry. Always ask open-ended questions to allow pa-tients to describe theirsymptoms. Patients com-plaining of pain or decreasein vision need to be evalu-ated urgently. The usualquestions on the durationand chronology of com-plaints are elicited. In addi-tion, contact lens historymust be determined to assist
MANAGEMENT PEARLS
Fig. 1: Contact Lens PeripheralUlcer
Fig. 2: Contact lens acute red eye(CLARE)
Fig. 3: Giant papillary conjunctivi-tis
Fig. 4: Deposits on a soft contactlens lens
319January, 2004 DOS Times - Vol.9, No.7
in the diagnosis. Determinewhat kind of contact lens thepatient wears and how theyare being worn. What is theusual wearing time eachday? How old are thelenses? Moreover, if thelenses are still in the eyewith symptoms. Informa-tion on cleaning and disin-fection is also necessary.Find out what solutions arebeing used at the present.
b. Record the informa-tion on an examination orfollow-up sheet. This be-comes important when thesame patient returns for afollow-up.
c. Evaluation and man-agement begins with evalu-ation of the contact lens andeye on removal of contactlens. In choosing appropri-ate management option, it isnecessary to differentiatethose ocular changes thatcan be considered physi-ologically acceptable fromthose which are pathologi-cal. Any infiltrate on the cor-nea is clearly seriouswhereas mild edema may bephysiologically acceptable.Specific management op-tions are detailed in the sec-tion describing complica-tions above. Generally con-tact lens management op-tions include replacementwith a new lens of same oranother material and design,alter care regime and wear-ing mode. A common un-derlying problem of contactlens wear is build up of vis-ible or in-visible deposits inthe soft contact lens matrix.Advice to use frequent dis-posable lenses, is therefore isa common practice in pa-tients when lens spoilage isfrequently suspected. Lenscare regimen should be al-
tered if there is evidence ofsymptoms from use of a par-ticular solution. Hydrogenperoxide based solutions area good alternative in sensi-tive patients. More chroniccomplications such as pap-illary conjunctivitis orvascularisation will need areduction in wearing timeand even cessation of lenswear.
Preventing Contact-LensComplications before theystart
Creating loyal contactlens patients is throughteaching them to be smarterand safer contact lens wear-ers. Some of the steps thathelp are introduced below:
a. Screening for safercontact lens patients: Per-form a thorough pre-fitscreening to choose safercontact lens patients. It is im-portant that patient’s expec-tations and motivation areunderstood and if requiredpatient is appropriatelycounseled. Ocular healthhistory including prior dis-eases and surgery on theeye, medications currentlyinstilled in the eye, allergiesand nature of occupationmust be elicited pointedly.Some patients may be betteroff with spectacles than con-tact lenses and should bediscouraged at the begin-ning itself. For patients al-ready wearing contactlenses information on typeof lens worn, wear time andsubjective assessment ofcomfort will provide direc-tion to the change in contactlens material, design andwear.
b. Regular return visits:Every contact lens wearingpatient needs evaluations at
periodic intervals evenwhen they do not havesymptoms. The first followup visit should be scheduledafter a week and thereafterat 2 weeks, one month, andevery six months. Intervalsbetween follow up visitscould vary depending uponcontact lens history. Regularappointments enable you toverify patients’ compliance,answer their questions, andmaintain their ocular healthbetter overall. During eachvisit, ask patients how manylenses they have left andhow often they replacethem. If their answers differsignificantly from your ex-pectation be prepared toprobe further and ask why.Your patient may be stretch-ing out the replacementcycle. If so, you’ll need againto stress the importance ofsticking to the prescribed in-terval.
c. Care regimen. It is im-portant that patient receivesand understands correctlythe contact lens applicationand removal procedure andcare regime. It is importantto deliver to the patient writ-ten care instructions also. Atevery follow-up visit, prac-titioner and wearer shouldgo over the specific lens-careregimens. Verifying that pa-tients follow a proper lens-care regimen can help enor-mously.
d. Dos and don’ts: Thepatient should be educatedin the various dos anddon’ts. This helps provideclearer instructions. Handwashing, cleaning the lenscase and lens inspectionshould all be emphasized tothe patient as well as neverre-using lens care solutionand never using saline or
water to wet lens. It is alsoimportant to present symp-toms associated with adap-tation to contact lens wear toallay unfounded fears andinsignificant complaints. Pa-tients must be encouraged toseek advice from trainedpractitioners rather thanfriends or relatives who maynot have appropriate infor-mation.
In conclusion, while weare fortunate today to havetechnology that provides forhealthy contact lens wear inour patients, complicationscan and do occur. Three cri-teria are important to pro-viding superior care to ourpatients:a. Making sensible selec-
tions in lenses and pro-spective patients whenprescribing
b. Being suspicious of earlysigns of ocular compro-mise
c. Appropriately educatingpatients how to avoid po-tential risks.
Further ReadingThe IACLE Contact lens course
modules. International asso-ciation of contact lens educa-tors (Publisher), Sydney, Aus-tralia.
Donshik P, Porazinski A. GiantPapillary Conjunctivitis inFrequent-Replacement Con-tact Lens Wearers: A Retro-spective Study. Tr Am OphthSoc 1999; 97:205-220.
Pamela Capaldi and Barr J (Eds).Seven steps to better patientcare- an educational resourcefor contact lens assistant. Con-tact lens spectrum Supple-ment November 1994.
Saini JS, Rajwanshi A and Dhar S.Clinicopathological correla-tion of hard contact lens re-lated changes in tarsal con-junctiva by impression cytol-ogy. Acta OphthalmoI.1990;68:65-70.
MANAGEMENT PEARLS
320January, 2004 DOS Times - Vol.9, No.7
The symptom complex ofasthenopia and ocular dis-comfort makes up for a largepart of the ophthalmo-logist’s practice. Conver-gence insufficiency probablyremains the most commoncause of muscular astheno-pia. The recognition and ap-propriate treatment of thiscondition requires a goodunderstanding of the inter-play of the factors affectingthe near vision complex i.e.accommodation, conver-gence and miosis. To theuninitiated and the ignorant,it can be a harrowing expe-rience to obtain patient sat-isfaction.
Not much can be said be-yond the clinical descriptionof the condition given byvon Graefe in 1855“………such patients com-plain of eyestrain and a sen-sation of tension in andabout the globes….afterbrief periods of reading, theletters start to blur and runtogether….. crossed diplo-pia occurs with near workand often one eye is closedor covered while reading toobtain relief from visual fa-tigue…” The profile of thepatient presenting with thiscondition is as varied as thepresentation itself. Typi-cally, the subject is a young
adult who is either in the se-nior school or in the collegeand is prone to developingcomplaints when nearingthe examination period dueto the stress of studying forextended periods of time.There is also a growing seg-ment of population thatspends a considerable amo-unt of time at the computerterminals and present witha symptom complex oftenlabeled as the VDU (VisualDisplay Unit) syndrome.Convergence insufficiencyalso plays a significant partin this group. The symptomsare aggravated by ill health,poor sleeping habits andanxiety.
There are numerousother situations where con-vergence insufficiency isprone to develop. Patientswith higher grades ofametropia also develop con-vergence insufficiency. Withrefractive errors more than+5 to +6D, the patient doesnot accommodate and witherrors of -6D or more, theydo not have the necessity todo so. The third clinical sce-nario is of the presbyopewho starts to wear the nearcorrection for the first time.In all these situations thereis a lack of accommodationand hence an absence or re-duction of the accommoda-tive convergence. This re-sults in a relative divergencethat puts a strain on the fu-sional convergence.
Diagnosis1. Remote Near Point of
Convergence (NPC): is one ofthe most consistent findings.
Normal NPC:Ahildren : 6-10 cmAdults : 5-8 cm
w Traditionally the NPChas been measured byslowly moving a targetlevel with the nasion to-wards the eyes until thepatient perceives diplo-pia or the examiner notesa break in fusion and de-viation of the eyes. Instru-ments like the RAF scaleuse this principle
w Other modifications in-clude documentation ofthe recession of the NPCon repetitive measure-ments by 4-8 cm. Normalpersons show a recessionof approximately 1 cm
w A significantly differentbreak point and recoverypoint is also seen
w Inability to sustain con-vergence at near (10 cm)for at least 60 seconds isalso abnormal. This re-sults in asthenopia de-spite normal fusionalconvergence values.
2. Reduced Fusional conver-gence at near fixation
Normal fusional range:35-40 pd BO at near fixation3. Reduced AC/A ratio
Normal AC/A ratio bythe gradient method: 3-5pd/D4. A normal age appropriate
near point of accommodation(NPA)5. Variable amount of exopho-ria at near fixation. However,patients may also exhibit ortho-phoria and esophoria
Management1. Optimal refractive
correction: In those caseswhich have an identifiablecause of the convergence in-sufficiency, such as high un-corrected refractive errors,these have to be optimallycorrected. Low myopia (< -1D) is often secondary to theconvergence insufficiency,which leads to a stimulationof the accommodation in aneffort to increase the accom-modative convergence. Insuch cases, tackling the con-vergence insufficiency bymethods enumerated belowwould be sufficient.
2. Orthoptic treatmentforms the mainstay of thetreatment of convergence in-sufficiency. The goal of thetreatment is to increase thefusional range at near fixa-tion. Extensive office basedand home based treatmentstrategies are followed bydifferent authors. Optomet-ric vision therapy usually in-corporates the prescriptionof specific treatments in or-der to:w Normalize the near-point
of convergencew Normalize fusional ver-
gence ranges and facilityw Eliminate suppression
Dr. Rajendra Prasad Centre forOphthalmic Sciences,New Delhi
MANAGEMENT PEARLS
321January, 2004 DOS Times - Vol.9, No.7
w Normalize associated de-ficiencies in ocular motorcontrol and accommoda-tion
w Normalize accommoda-tive/convergence rela-tionshipNear point of conver-
gence exercises: An accom-modative target, such as thepoint of a pencil (i.e., pencilpush-ups), is placed remoteto the patient’s near point ofconvergence and graduallybrought toward the tip ofthe nose with the patientconverging to avoid diplo-pia. Just before there is abreak in fusion, the patientholds fixation on the targetfor 50 seconds and then re-laxes for 10 seconds. This so-called “sustained push-up”is repeated 5 times in succes-sion, 2-4 times a day, untilthe patient is able to holdsustained fixation to about10 cm from the eyes. Thepatient has to be taught toappreciate physiologicaldiplopia. Often if the targetis brought close enough, thepatient may experience de-viation of one eye and thepurpose of the exercise maybe lost. The exercises can betapered and then used on anas-needed basis when thepatient notices a recurrenceof symptoms. One of thedrawbacks of the home ex-ercises is that the patientsconsider it too simplistic andoften lose interest in themand discontinue them. Acourse of the office-basedexercises on the synopto-phore often helps.
A Simple Home Ortho-ptic Trainer (SHOT) de-signed at the R P Center maybe used. This method uti-lizes a dark circle painted oneither side of a folded paper
such that the circles can besuperimposed and the pa-per slid on a scale. The circleon one side has a cross on thetop and the other side at thebottom. The patient has tofuse the two circles such thatboth the crosses are visibleon the circle. The fusion isthen maintained for about50 seconds as close to thenose as possible and re-peated 4-5 times in succes-sion 4-5 times a day. A pro-gressive decrease of the dis-tance between the paper andthe eyes indicates improve-ment.
Other forms of conver-gence training: Base-outprism reading and stereo-gram cards may be used toimprove fusional conver-gence. New, affordable com-puterized fusional vergencetraining programs (eg, Com-puter Orthoptics) are avail-able. These self-paced pro-grams can be used on a per-sonal computer at thepatient’s home.
Base-in prisms for nearonly: These prisms can beground into a separate pairof reading glasses, or Fresnelmembrane prisms can be fit-ted over the reading seg-ment of the patient’s bifo-cals.
Duration of TreatmentTreatment duration will
depend upon the particularpatient’s condition and asso-ciated circumstances. Themost commonly encoun-tered convergence insuffi-ciency usually requires 24 to32 hours of office therapy.Uncomplicated conver-gence insufficiency charac-terized by only a remotenear point of convergence:up to 12 hours of office
therapy.Convergence insuffi-
ciency complicated by re-stricted fusional ranges needan additional 12 hours of of-fice therapy and those withan accommodative elementneed up to an additional 8hours of office therapy.
3. Surgery: The decisionto proceed with surgeryshould be made with cau-tion and only after all ortho-ptic efforts have failed. Bilat-eral medial rectus resectionsare usually the most effec-tive operation for this con-dition preferably as an ad-justable procedure. How-ever, the patient should bewarned about the possibil-ity of uncrossed diplopia atdistance fixation after sur-gery. This typically resolveswithin 1-3 months postop-eratively. The exophoria atnear usually recurs after sev-eral years, although mostpatients remain asymptom-atic for unknown reasons.
Accommodation SpasmDefinition: brought by
the spasm of the near com-plex leading to convergence,pseudo myopia and miosis.
Symptoms• Blurred often fluctuating
vision depending onpatient’s refractive status
• Macropsia• Asthenopia during close
work• Pain (eyebrows/ head-
ache)• Poor concentration
Typically, the patient is ayoungster, under stress, thesymptoms developing afterprolonged and intense peri-ods of near work.
Signs
1. Significant differencein the refractive error withand without cycloplegia
2. Miosis3. Convergence anoma-
lies usually variable (excess)
Management1. Identify and treat the
organic cause: spasm due toirritation of the parasympa-thetic system or oculomotornerve.
cient in most of the casesalong with advise regardingocular hygiene and properreading habits
3. In cases of large re-fractive errors, the error iscorrected. Initially, the hy-permetropia is slightly un-der corrected and thengradually increased.
4. Marked spasms needto be treated by usingcycloplegics such as atro-pine for several weeks.
5. The negative relativeconvergence, which devel-ops once the spasm is cor-rected, may be overcome byorthoptic exercises. Orthop-tics form the mainstay oftreatment in cases of conver-gence insufficiency with lowmyopia
Accommodational InertiaDef: condition where a
difficulty in changing the ac-commodative state from inedistance of fixation to an-
MANAGEMENT PEARLS
322January, 2004 DOS Times - Vol.9, No.7
other, manifested by an in-ability to change focusquickly.
Etiology: Unilateral-Adie’s syndrome
Bilateral- anisometro-pia, poor general health, fa-tigue
Clinical features: com-plaints of intermittent blur-ring of vision, with a delayin the ability to change focusfor a particular distance es-pecially from distance tonear; seen in the middle age
group (>30 years) but some-times even in adolescence.Accommodation range is be-low normal for the age.
Management: correct re-fractive errors, improve thefusion range and conver-gence through exercises toalleviate the asthenopia.
Accommodational Paraly-sis
Def: Complete inability toaccommodate
Etiology: Ciliary muscle
paralysis due to any cause-drugs, trauma, third nervepalsy.
Clinical features:Myope patient is gener-
ally asymptomatic; the hy-permetrope is unable to fo-cus at any distance.
The emmetrope has de-creased vision for near only.
Management:w Rule out an associated
convergence paralysis- if
present orthoptic exer-cises started.
w Convex lens with base inprisms prescribed fornear
P-1773Prasad RahulC/O Dr. Ram Kumar PrasadPrasad Nivas, BariatuBehind Sirdi Sai HospitalRanchi-834009
323January, 2004 DOS Times - Vol.9, No.7
Letters to Editor
Dear Editor,Endophthalmitis is defined as an
inflammation of inner coats of theeye associated with exudates in thevitreous, which may be infectious ornon infectious in origin. Althoughthe incidence of intraocular infec-tions after cataract surgery hassharply declined over the past 3-4decades since the advent of aseptictechniques and the use of prophylac-tic antibiotics, endophthalmitis stillremains one of the most dreadedcomplications that an ophthalmicsurgeon has to face.
The mainstay of treatment forpost-operative endophthalmitis isintravitreal injection of antibiotics.Usually a combination of two anti-biotics is chosen which are selectedbased on their activity against coagu-lase-negative staphylococci (the mostcommon cause of endophthalmitis),and gram negative bacilli. The mostcommonly used and effective com-bination for this purpose at presentis Vancomycin (1 mg / 0.1 ml) andceftazidime (2.25 mg / 0.1 ml).
Intravitreal injection of antibioticsshould be given in the operation the-
atre under proper aseptic precau-tions. It is usually performed undertopical anaesthesia; however, in un-cooperative patients, peribulbar orretrobulbar anesthesia could be ad-ministered.
The most common site for admin-istering intravitreal injection isinferotemporally 3.0 mm from thelimbus in aphakic and 3.5 mm inpseudophakic eyes. Initially around0.5 cc vitreous should be aspiratedwith a 21-gauge needle for makingsmears as well as for culture sensi-tivity; then antibiotics are injectedsequentially into the vitreous cavitywith a 26 gauge needle. In case of drytap, anterior chamber paracentesiscould be done for the same and evenmore importantly, for bringing downthe IOP prior to the intravitreal in-jection.
It is not necessary to use 2 differ-ent needles for injecting the 2 antibi-otics though different syringes aremandatory. The needle should bekept facing towards the centre of theglobe. The bevel of the needle shouldbe dented upwards towards the cor-nea. The antibiotics should be taken
in 2 separate glass tuberculin syringes.Disposable tuberculin syringes shouldbe avoided. This is so because it is pos-sible to inject the antibiotic slowly dropby drop with a glass tuberculin syringeby rotating the plunger while pushingit forward. This motion is not possiblewith a disposable syringe. Thus, a jetof fluid is more likely to be injectedwith a disposable syringe.
As per EVS, systemic antibioticshave no added role in patients beingtreated by intravitreal injections orvitrectomy. However as a rule we doadminister systemic Ciprofloxacin200mg. IV or 750mg. oral twice a dayto patients of endophthalmitis. The ra-tionale for this decision is that systemicCiprofloxacin does have a significantpenetration into the vitreous cavity asopposed to the systemically adminis-tered drugs tested during the EVS inmost of their patients.
Sanjeev Naniwal MD, DNB,
S.P. Garg MD, H. K. Tewari, MD
R.P. Centre for Ophthalmic Sciences,AIIMS, New Delhi,
Dear Dr. Titiyal,We are very pleased to see our
published review article on OVD inthe the DOS times. I also enjoyedsome of the previous issues of theDOS times. Congratuations to youand your team for disseminating rel-evant knowledge among the oph-thalmic community.
Dr. Suresh K. Pandey,John A Mohan Eye Centre,
5th Floor, Department ofOphthalmology & Visual Sciences
University of Utah,50 North Medical Drive,
Salt Lake City, Utah- USA
LETTERS TO EDITOR
Practical Tips to Manage Post-operative Endophthalmitis
Keep April 3-4, 2004 Freefor
ANNUALCONFERENCE
Delhi Ophthalmological Society
324January, 2004 DOS Times - Vol.9, No.7
Umbilical cord serum therapy leads tofaster healing of the persistent cornealepithelial defects.Vajpayee RB, Mukerji N, Tandon R, Sharma N, Pandey RM,Biswas NR, Malhotra N, Melki SA.Br J Ophthalmol. 2003 Nov; 87(11): 1312-6Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS,New Delhi.
Authors evaluated umbilical cord serum therapy as ameans of promoting the healing of persistent corneal epithe-lial defects. The study design was a prospective randomisedcontrolled clinical trial. 60 eyes of 59 patients were dividedinto two groups, 31 in the cord serum group and 29 in theautologous serum control group. Epithelial defects measur-ing at least 2 mm in linear dimension resistant to conventionalmedical management were included. Serial measurementsof the size of the epithelial defects-namely, two maximumlinear dimensions perpendicular to each other, and the areaand perimeter was done at start of therapy and follow up days3, 7, 14, 21. The data were analysed by the non-parametricWilcoxon rank sum test using STATA 7.0. RESULTS: Themedian percentage decrease in the size of the epithelial defectwas significantly greater in the cord serum group at days 7,14 and 21 (p<0.05) when measured in terms of the area andperimeter. A greater number of patients showed completere-epithelialisation with umbilical cord serum (n = 18) thanwith autologous serum (n = 11) (Pearson chi = 0.19). Noneof the patients reported any side effects or discomfort witheither treatment. They conclude umbilical cord serum leadsto faster healing of the persistent corneal epithelial defectsrefractory to all medical management compared to autolo-gous serum.
Acute attack of angle closure glaucoma isassociated with significant decrease in thecorneal endothelial cell densitySihota R, Lakshmaiah NC, Titiyal JS, Dada T, Agarwal HC.Clin Experiment Ophthalmol. 2003 Dec;31(6):492-5.Rajendra Prasad Centre for Ophthalmic Sciences, AII MS,New Delhi.
Authors studied the corneal endothelium and pachy-metry in eyes with different subtypes of primary angle clo-sure glaucoma (PACG), as compared to controls. A cross-sec-tional study was conducted on 30 consecutive patients in eachsubtype of PACG, subacute, acute and chronic, and 30 ageand refraction matched controls. The parameters recordedincluded gonioscopy, optic disc evaluation, applanationtonometry, specular microscopy and central ultrasonicpachymetry. The mean endothelial cell counts in the fourgroups were as follows: subacute PACG 2396 +/- 271 cells/mm2, acute PACG 1597 +/- 653 cells/mm2, chronic PACG2229 +/- 655 cells/mm2 and controls 2461 +/- 321 cells/mm2. The mean endothelial cell count in the fellow eyes of
JOURNAL ABSTRACTSsubacute PACG, acute PACG and chronic PACG patientswas 2294 +/- 305 cells/mm2, 2388 +/- 226 cells/mm2 and2108 +/- 203 cells/mm2, respectively (NS). The acute PACGpatients had significantly lower endothelial cell counts (P <0.001) as compared to the other three groups. Eyes in whichthe acute attack of angle closure persisted for less than 72 hhad a mean endothelial cell count of 2016 +/- 306 cells/mm2,as compared to 759 +/- 94.4 cells/mm2 in eyes with an at-tack lasting for 72 h or more (P < 0.001). The endothelial countwas also significantly lower in eyes with chronic PACG ascompared to control eyes (P < 0.001). There was increasedpleomorphism and polymegathism of the corneal endothe-lial cells seen in eyes with resolved acute and chronic PACG.The mean central corneal thickness was 531.4 +/- 25.3 microm in eyes with subacute PACG, 567.9 +/- 37.3 micro m in eyeswith acute PACG, 526.4 +/- 31.9 micro m in eyes with chronicPACG and 525 +/- 12.6 micro m in control eyes. The acutePACG eyes had a significantly higher corneal thickness (P< 0.001) when compared to all the other groups. They con-clude there is a significant decrease in the corneal endothe-lial cell density in eyes that have had an acute attack of angleclosure glaucoma and in eyes with chronic PACG. The en-dothelial cell population in eyes with sub-acute PACG andin the fellow eyes of all subtypes of PACG is not significantlydifferent from the normal population.
Most ocular injuries in children are prevent-able and occur from unsupervised gameslike bow and arrow and firecracker, whichcan lead to significant visual loss.Saxena R, Sinha R, Purohit A, Dada T, Vajpayee RB,Azad RV. Indian J Pediatr. 2002 Oct;69(10):863-7.Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS,New Delhi, India.
The study was aimed to identify the causes, demographicand clinical profile and evaluate final visual outcome ofpediatric ocular injuries. 204 children aged fourteen years orless presenting to the emergency services of a tertiary carecentre with ocular injury were included. Demographic data,nature and cause of injury, duration between injury andpresentation to an ophthalmologist and the diagnosis wererecorded. Evaluation of visual acuity, anterior segment andfundus were done. All patients were appropriately managedand followed up on days 1, 7, 1 month, 3 and 6 monthsMajority of injuries occurred in children of 5 years and older(87.7%). There were 133 (65.1%) boys and 71 (34.9%) girls.49 (24%) cases presented within 6 hours of injury while 70(34.3%) presented after more than 24 hours after trauma.Most common cause of injury was bow and arrow (15.2%)followed by household appliances (14.3%). Closed globeinjuries accounted for 42.2% injuries, open globe for 53.9%and 3.9% were chemical injuries. Best corrected visual acu-ity of 6/12 or better was achieved in 79 eyes (91.86%) in closedglobe group. However, only 17 eyes (15.45%) in open globegroup could achieve this.
325January, 2004 DOS Times - Vol.9, No.7
Annual Conference ofDELHI OPHTHALMOLOGICAL SOCIETY
Abstract received on:____________________________________________________Please Note:w All Abstracts should compulsarily be accompanied by full text along with the illustrations and
photographs. An MS Word file of the same is also required on a 31/2 floppy disk.w Session - I: Dr. A.C. Agarwal Trophy Session.w Session - II: Winner of Best Paper in this session will be awarded "Certificate of Merit ".w ONLINE SUBMISSION: (Submission can also be made online through the DOS website:
www.dosonline.orgw Video in (CD, VHS) should be submitted along with abstracts.w Best Poster and Best Video presentation will be awarded trophy and prize money.
3th & 4th APRIL, 2004
* ABSTRACT SUBMISSION FORMTo be sent to: Dr. Jeewan S. Titiyal , Organizing Secretary, # 476, 4th floor,Dr. R. P. Centre for Ophthalmic Sciences, AIIMS, Ansari Nagar, New Delhi 110 029 (INDIA)Deadline for submission of abstracts: 1st February, 2004Deadline for submission of complete text: 15th March, 2004
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ABSTRACT FORM
FP Poster Video
TITLEAUTHORSINSTITUTIONTYPE OF PRESENTATION
326January, 2004 DOS Times - Vol.9, No.7
Annual Conference ofDelhi Ophthalmological Society
Date: April 3 & 4, 2004 New Delhi
A Preview ofOphthalmic Panorama 2004• Plenary Session • Spot Light
• Question Time • Ophthalmic Debates• Wet Labs • Symposia
• Video Assisted Skill Transfer Courses• Instruction Course
• And Many More
"REGISTRATION FORM FOR DOS ANNUAL CONFERENCE (2004)
Name _________________________________ Spouse Name____________________________
Mail Registration form with Demand Draft/Cheque to: Dr. Jeewan S. Titiyal , Organizing Secretary,Room No.476, Dr. R.P. Centre for Ophthalmic Sciences, A.I.I.M.S., New Delhi-110029.
CONFERENCE REGISTRATION
327January, 2004 DOS Times - Vol.9, No.7
DOS QUIZ NO. 7
Rules:l Please send your entries to the DOS office latest by 25th December, 2003.l Prize Rs. 500/- Courtesy: Syntho Pharmaceuticalsl Quiz Trophy will be given to the member who answers maximum number of quizes in a year during the
Annual GBM of DOS.
DOS QUIZ NO. 71. Dose of Melhylyprednisolone in traumatic optic neuropalty ............................................................................................
2. Tight lens syndrome is common in which type of lens .......................................................................................................
3. Which anliglaucoma drugs are contra indicated in inflammatory glaucoma .................................................................
4. Most common cause of pupil involving 3rd N palsy is ........................................................................................................
5. Most common Orbital mass lesion in adult ..........................................................................................................................
6. Most common location for Retinoschisis ...............................................................................................................................
7. Most common symptomatic choroidal metastasis ...............................................................................................................
8. Most common cause of 4th nerve palsy in children ..............................................................................................................
9. Most common cause of chronic canaliculitis is ....................................................................................................................
10. Most common corneal stromal dsytrophy to recur in graft is ............................................................................................
Answers for the DOS Quiz No. 5
1. Osler’s sign is seen in Alkaptonuria
2. Site of lesions in one and half syndrome PPRF and ipsilataral MLF
3. “Double floor” sign in x-ray skull is found in Pitutary Adenoma
4. “Salmon Patch Haemorrhage” is seen in Sickle Cell Anemia
5. Vogts triad is commonly seen in Acute Angle Closure Glaucoma
6. Most common type of paranasal mucocele Frontal Mucocele
7. pH of Tear film is 7.4
8. Visual field is largest for which colour Blue
9. Best Diagnostic test for “Best Disease” is EOG
10. Corneal ulcer with “cracked wind shield” appearance is caused by Nocardia/Mycobacterium Fortitutum
Winner of DOS Quiz No. 5: Dr. Deepika Seth (Congratulation)
328January, 2004 DOS Times - Vol.9, No.7
As the year came to an end a grand era also came to an end, as we laid down the mortal remains of a legend:Professor Prem Prakash. He was PP for most of us. He was the father figure in Strabismus in India. He was a manof convictions and courage. He lived his life on his principles. Even God could not deny him his right to leave thisworld, in saddle.
He belonged to Solan, Himachal Pradesh and was born on the 8th of August 1936. He had done his MBBS fromMedical College Amritsar (1959) and M.S. in Ophthalmology from Dr. Rajendra Prasad Centre for Ophthalmic Sci-ences, AIIMS in 1962. He acquired his strabismus training under Prof Cuppers (Professor of Pleoptics) at Giesen,West Germany (1968-69) and got his FDAAD where he also acquired a working knowledge of German.
Not many know that he was a fine cataract surgeon especially for the Smith-Indian tumbling technique forIntracapsular cataract extraction (ICCE). It was he who was asked to demonstrate this Indian contribution in ophthalmology to the world, tothe august delegates of International Congress of Ophthalmology, Delhi, 1962, where he showed his “Lever-ledge-tumble” principle.
He had his share of struggles in the early part of his life as he served in various capacities as Eye and ENT specialist in HimachalPradesh; Registrar at Dr. Shroff’s Charity Eye Hospital, Daryaganj and Ophthalmic Surgeon under the National Society of Prevention ofBlindness-India, before joining his ophthalmic alma-mater at AIIMS as lecturer in 1966. He rose to become a Professor(1985) and Chief ofRPC (1993) before his retirement in August 1996.
Retirement for him however just meant Re-tyre-ment like changing tyres of your car and he was on drive again. He had an activepractice in strabismus, as he worked at MM Eye Tech Institute, Centre for Sight and a clinic in Vikaspuri. After the loss of his life partner, PremKumari, he seemed to have lost the lust for life, but his “work-worship” continued unabated till the last, practising his principle of “Na dainyamna cha palaayanam” (Neither be meek nor seek escapism).
He was an ardent student of philosopy and was fond of Aurobindo’s works. It was a pleasure to discuss with him on any topic. He wasalso an excellent orator and could keep the audience spell-bound in a scientific talk without the props of slides even in today’s era.
His name became synonymous with Strabismus in India. He was the Founder President of the Strabismological Society of India, whichhe caringly nurtured. He was also the President of Delhi Ophthalmological Society. He was awarded the P Siva Reddy Oration of All IndiaOphthalmological Society. He also edited the Eastern Archives of Ophthalmology, Indian Journal of Orthoptics and Pleoptics and Strabiscopeand was on the Editorial Board of the Indian Journal of Strabismology and Pediatric Ophthalmology.
He is survived by his two sons, a grandson, and thousands of Strabismus fans. His legacy will live on by the examples he set forth by hispractice. He was a legend in Strabismus and his name shall always be imprinted in the hearts of all of us. A small poetic tribute shallsummarise our feelings for him.
At home you may have been PapaBut were PP for us few.And all who delved in squintSaw a father figure in you.
With you in lead we toiledWith you at head we grew.But a body without a headSo we shall miss you.
With all the cherished thoughtsThere is a “pleoptic” hopeTo prolong your after-imageWish there was an “alternascope”.
But, the circle of life rollsAnd physically we shall partWe assure you, Sir, foreverYou shall have a place in our heart.
As you embark on your final journeyTo a future of golden hueWe bid you a tearful farewellAuf wiedersehen, Adieu!
Good bye dear ProfessorA Goodbye to you! – Pradeep Sharma
Goodbye Professor Prem Prakash
Prof. Prem Prakash
329January, 2004 DOS Times - Vol.9, No.7
Name (In Block Letters) _________________________________________________________________________
S/D/W/o _____________________________________________________________ Date of Birth _____________
Dr. _______________________________ Member Ship No. ______________ Signature _________________
Seconded by
Dr. ________________________________ Membership No. ______________ Signature _________________
[Must submit a photocopy of the MBBS/MD/DO Certificate for our records.]
I agree to become a life member of the Delhi Ophthalmological Society and shall abide by the Rules and Regula-tions of the Society.(Please Note : Life membership fee Rs. 3100/- payable by DD for outstation members. Local Cheques acceptable,payable to Delhi Ophthalmological Society)
Please find enclosed Rs.____________in words ______________________________________________________ by
Dr._______________________________________________________________has been admitted as Life Member of
the Delhi Ophthalmological Society by the General Body in their meeting held on________________________________
His/her membership No. is _______________. Fee received by Cheque/DD No._______________ dated__________
drawn on __________________________________________________________________.
(Secretary DOS)
Stamp Size2 Colour
Photograph
330January, 2004 DOS Times - Vol.9, No.7
INSTRUCTIONS
1. The Society reserves all rights to accepts or reject the application.
2. No reasons shall be given for any application rejected by the Society.
3. No application for membership will be accepted unless it is complete in all respects and accompanied by a Demand Draft of Rs. 3100/- infavour of “Delhi Ophthalmological Society” payable at New Delhi.
4. Every new member is entitled to received Society’s Bulletin (DOS Times) and Annual proceedings of the Society free.
5. Every new member will initially be admitted provisionally and shall be deemed to have become a full member only after formal ratificationby the General Body and issue of Ratification order by the Society. Only then he or she will be eligible to vote, or apply for any Fellowshippropose or contest for any election of the Society.
6. Application for the membership along with the Bank Draft for the membership fee should be addressed to Dr. Jeewan S. Titiyal, Secretary,Delhi Ophthalmological Society, R.No. 476, 4th Floor, Dr. R.P. Centre for Ophthalmic Sciences, AIIMS, Ansari Nagar, New Delhi – 110029.
7. Licence Size Coloured Photograph is to be pasted on the form in the space provided and two Stamp/ Licences Size Coloured photographsare required to be sent along with this form for issue of Laminated Photo Identity Card (to be issued only after the Membership ratification).
Attention DOS Members
Applications are invited for DOS Fellowship for Partial FinancialAssistance to Attend International Conference(s). The last date forreceiving application is 31st January 2004.
For Details Please See Page No. 332.
DOS ElectionApplications are invited from Delhi
Members of Delhi Ophthalmological Society
for the post of : Vice President (1 Post)
The eligibility criteria for different post
prescribed in DOS Constitution (1998) will
be followed. Application should be submitted
on a plain paper duly proposed and seconded
by a member of DOS (not in arrears). Appli-
cation should reach Secretary Office latest by
10th February 2004 (2 p.m.). Last date of
withdrawal is 10th March, 2004 (5 p.m.)
Election will be held during the Annual DOS
Conference on 3rd April, 2004.
Secretary, DOS
W A N T E D1. Ophthalmologist with Excellent Operating
Skills. (Small Incision Cataract Surgery)
2. Ophthalmologist to Work in OPD and Camps.Salary Negotiable!!
Following Training Programmes are Offered in
MAHATHMA EYE HOSPITAL1. Fellowship in IOL and PHACO-1 Year.2. Short term Fellowship in General Ophthalmology 3 Months.3. One Month Phaco Training Programme.4. Two Month SICS Training Programme5. One Month SICS Training Programme6. 15 Days SICS Training Programme
Apply with resumes
For further details contact
Mahathma Eye Hospital35, 11th Cross,Thillai Nagar, Main Road,
The rate of technological and academic obsolescencein Ophthalmology has reached astronomical levels inrecent times. What was advanced yesterday may alreadybe obsolete today. The rapid strides in skills and knowl-edge have created a need for an extremely intensiveContinuing Medical Education programme.
DOS has always been in the forefront of efforts toensure that its members remain abreast with the latestdevelopments in Ophthalmology. Among the impor-tant objectives formulated by the founders of our consti-
DOS Credit Rating System (DCRS)
If any of the presentations is given an Award –Additional 20 bonus Credits.
Member who have earned 100 Credits, are enti-tled to:
a) Certificate of Academic Excellence in Ophthal-mic Practice.
b) 50% exemption of Registration fee at next An-nual DOS Conference.
c) DOS Travel fellowship for attending confer-ence. A member to be eligible for the fellowshipneeds to score 100 DCRS points.
If any member earns 200 Credits, he/she shall, inaddition to above, be awarded Certificate of Distin-guished Resource-Teacher of the Society.
tution was the cultivation and promotion of the Scienceof Ophthalmology in Delhi.
In a bid to strengthen our efforts in this direction andfulfil the vision of our society’s founders, DOS announcesthe DOS Credit Rating System (DCRS), the details ofwhich are given below. Our Primary objective is to pro-mote value-based knowledge and skills in Ophthalmol-ogy for our members and give recognition and credit forefforts made by individual members to achieve stand-ards of academic excellence in Ophthalmic Practice.
DOS announces a new era in Continuing Medical EducationDOS CREDIT RATING SYSTEM (DCRS)
(A new chapter in CME)Credits
1) Attending Monthly Clinical Meeting* † (For full attendence) 10
2) Making Case Presentation at Monthly Meeting** 15
3) Delivering a Clinical Talk at Monthly Meeting** 15
4) Free Paper Presentation at Annual Conference (To Presenter)** 15
5) Speaker/Instructor** in : Monthly Symposium 15
: Mid Term Symposium 15
: Annual Conference 15
6) Registered Delegate at Mid Term DOS Conference 20
7) Registered Delegate at Annual DOS Conference 30
8) Full Article publication in Delhi Journal of Ophthalmology/DOS Times 15
9) Letter to Editor/Correspondence in DOS Times 10——————————————————————————————————————————————
Institutional assessment for best performance willbe based on the total score of members who attenddivided by number of members who attended. In-stitutional assessment regarding decision to retainthe institute for the next year will be based on totalscore by all delegates who attend the meeting di-vided by average attendence of all 8 meetings.
Please note that the Institutions’ grading in-creases if the attendance at its meeting is higher (i.e.more than the average attendence of the eightmonthly meetings).——————————————————————* Based on Signature in DCAC** Subject to Submission of Full Text to Secretary, DOS† Credits will be reduced in case attendence is only forpart of the meeting.
DCRS
332January, 2004 DOS Times - Vol.9, No.7
ConferencesInternational: Two fellowships per year (two fellowships canbe awarded at a time if committee feels that papers are verygood)· Maximum of Rs. 25,000/- per fellowship will be sanctioned
National: Three fellowships per year (only for AIOS)· Maximum of Rs. 5,000/- per fellowship will be sanctioned
Eligibility:· DOS Life Members (Delhi Members only)· 75 or More DCRS Points· Accepted paper for oral presentation, poster, video or in-
struction course.
Time since last DOS Fellowship:Preference will be given to member who has not attended
conference in last three years. However if no applicant is foundsuitable the fellowship money will be passed on to next year.Members who has availed DOS fellowship once will not beeligible for next fellowship for a minimum period of threeyears.
AuthorshipThe fellowship will be given only to presenting author. Pre-
senting author has to obtain certificate from all other co-au-thors that they are not attending the said conference or notapplying for grant for the same conference. (Preference willbe given to author where other authors are not attending thesame conference). If there is repeatability of same author groupin that case preference will be given to new author or newgroup of authors. Preference will also be given to presenterwho is attending the conference for the first time.
Quality of PaperThe applicant has to submit abstract along with full text to
the DOS Fellowship Committee. The committee will reviewthe paper for its scientific and academic standard. The papershould be certified by the head of the department / institu-tion, that the work has been carried out in the institution. Incase of individual practitioner he or she should mention theplace of study and give undertaking that work is genuine. Thefellowship committee while scrutinizing the paper may seekfurther clarification from the applicant before satisfying itselfabout the quality and authenticity of the paper. Only Singlebest paper has to be submitted by the applicant for review (6copies). Quality of the paper will carry 50% weightage whiledeciding the final points.
Poster and VideoThe applicant will need to submit poster and video for re-
view.
Credit to DOSThe presenter will acknowledge DOS partial financial as-
sistance in the abstract book / proceedings.The author will present his or her paper in the immediate
next DOS conference and it will be published in DJO/DOSTimes.
Delhi Ophthalmological Society Fellowship for PartialFinancial Assistance to Attend Conferences
Points Awarded1) Age of the Applicant Points
a) £ 35 years 10b) 36 to 45 years 07c) 45 years plus 05
2) Type of Presentationa) Instructor/ Co-instructor of Course 12b) Free Paper (Oral) / Video 07c) Poster 05
4) DCRS Rating in the immediate previous yeara) 75-150 05b) > 150 08c) < 75 not eligible for fellowship
Documents· Proof for age. Date of Birth Certificate· Original / attested copy of letter of acceptance of paper for
oral presentation / video / poster or instruction course.· Details of announcement of the conference· Details of both International & National Conferences at-
tended in previous three years.· Copy of letter from other national or international agency
/ agencies committing to bear partial cost of conference ifany.
· At least one original document should be provided, that isticket, boarding pass or registration certificate along withattendance certificate of the conference.
· Fellowship Money will be reimbursed only after submis-sion of all the required documents and verified by the com-mittee.
· Undertaking from the applicant stating that above giveninformation’s are true.
· If found guilty the candidate is liable to be barred for fu-ture fellowships.Dr. J C Das (President DOS), Dr. Gurbax Singh (Vice Presi-
dent DOS), Dr. Kamlesh (Editor) Dr. Lalit Verma (Library Officer),Dr. Sudipto Pakrasi (Member) and Dr. Jeewan S. Titiyal (SecretaryDOS) will be the members of DOS Fellowship for Partial Fi-nancial Assistance to Attend Conferences Committee.
Application should reach Secretary’s office addresses toPresident DOS before 31st July and 31st January for interna-tional conference and before 30th September for national con-ference. The committee will meet thrice in a year in the monthof August, October and February with in 2 weeks of last dateof receipt of applications. The committee will reply within fourweek of last date of submission in yes/no to the applicant. Nofellowship will be given retrospectively, that means prior sanc-tion of executive will be necessary.
Dr. Jeewan S. Titiyal, Secretary Delhi Ophthalmological SocietyR.No. 476, 4th Floor,Dr. R.P. Centre for Ophthalmic SciencesAIIMS, Ansari Nagar, New Delhi – 110029
DOS FELLOWSHIP
333January, 2004 DOS Times - Vol.9, No.7
Respiratory drugs
Oxygen Retinopathy of prematurity.
Cardiovascular system drugs
Digitalis Disturbances of color vision, scoto-mas, photopsia.
