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Contact Lens & Anterior Eye
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ehabilitation of vision disabling corneal opacities: Is there hope without cornealransplant?
irti Singh ∗, Divya Jain, Kunal Teliuru Nanak Eye Centre, Maulana Azad Medical College and Affiliated Hospitals, New Delhi, India
r t i c l e i n f o
rticle history:eceived 10 May 2012eceived in revised form2 September 2012ccepted 8 October 2012
eywords:igid gas permeable lensesorneal opacity
rregular corneal astigmatismediatric lens fitting
a b s t r a c t
Objective: To evaluate the efficacy of contact lenses in visual rehabilitation of a series of patients withcorneal scars/opacities.Method: Retrospective review of case records of 158 patients (n = 162 eyes) with poor vision subsequentto corneal scar/opacity, who underwent contact lens fitting, was done. Primary outcome assessed wasquantum of additional improvement in vision with rigid gas permeable (RGP) or soft lenses over specta-cles. Success was defined as visual improvement of ≥2 lines over that of spectacles and/or improvementof vision to ≥20/60 (LogMAR 0.48).Results: Rigid gas permeable lenses were fitted in 137 eyes and soft contact lenses in 25 eyes. Lenses weresuccessful in improving visual acuity by two or more lines over that of spectacles in 70% eyes (113 of 162eyes), of which RGP lens accounted for 85% (96 of 113 eyes). Alternative outcome of success was defined
phakiaoft lenses
as attainment of reasonable functional vision of >20/60 (LogMAR 0.48). This could be achieved in 65%cases (105 of 162 eyes) of which 83% (88 eyes) were with use of RGP lenses. Almost one-fourth (23.4%)patients were children less than 15 years old. Soft contact lenses were attempted in 25 instances, whereRGP lens could not be fitted and were successful in 17 (68%) of these. All these 17 patients were aphakes.Conclusions: Rehabilitation of corneas with visually disabling corneal opacities is possible with usage ofappropriate contact lenses even in young children.
Corneal scarring leads to diminution of visual acuity either byight scatter due to an irregular cornea as in nebular, macularorneal opacity or by direct obscuration of rays in case of a leuco-atous opacity. Such patients often have co-existing high irregular
stigmatism which is not easily amenable to optical correction withpectacles. Global estimates suggest that corneal opacities accountor 1.5–2.0 million new cases of monocular blindness every year1,2]. In India, the prevalence of corneal opacities at 7.3 per 1000opulation makes it the fifth common cause of vision deprivation3]. The ideal treatment for many such cases would be corneal graft-ng, but scarcity of donor corneas limits this option in developingountries like ours. Even among those who are able to get a suitableorneal graft, the post operative course of a grafted eye is event-ul, requiring regular monitoring and medications. This translates
nto additional treatment time and cost in the management. Visualehabilitation in many of these traumatized corneas is further com-licated by additional co morbidity of post traumatic unilateral
∗ Corresponding author at: C-1/1, FF, West Enclave, Pitampura, New Delhi 110034,ndia. Tel.: +91 9968604334/11 27011233.
h Contact Lens Association. Published by Elsevier Ltd. All rights reserved.
aphakia, which mandates contact lens correction to prevent ani-sometropia and subsequent amblyopia [4]. All these factors makecontact lens an attractive proposition for rehabilitation of suchcases.
Contact lenses help in negating the irregular astigmatism due tocorneal scarring, by providing a smooth refracting surface [5–11].The tear film underneath the contact lens also helps to neutralizesurface irregularities. Prior studies have reported successful useof rigid gas permeable (RGP) lenses in improving vision in casesof nebular/nebulo-macular corneal opacities [12,13]. Limited pub-lished data on this aspect is available from the developing world[14–16]. In this case series, we share our experience in fitting con-tact lenses over severely traumatized/damaged corneas spanninga nine year period.
2. Material and methods
Review of case records of patients with visual diminution dueto corneal scarring (post trauma or keratitis) seen, over past nine
year period from 2002 to 2010, was done. Assessment performedfor these cases included uncorrected visual acuity, best spectaclecorrected visual acuity, slit lamp biomicroscopy, corneal health,lens status and posterior segment evaluation. All cases were
1 ± 0.53 (mean + SD)Median 1, with IQR from 0.6 to 1.3
<20/200 (1.0 LogMAR) in 89 eyes,20/120 (0.7 LogMAR) to 20/40 (0.30
LogMAR) in 73 eyesPost lens fit visual acuity 0.45 ± 0.38 (mean + SD)
Median 0.3, with IQR 0.2–0.6Better than or equal to 20/60 (0.48 LogMAR)
in 105 eyesBetter than or equal to 20/32 (LogMAR 0.2)
in 53 eyesImprovement in lines with
CL over spectacles5 ± 2.93 (mean + SD)Median 3 lines with IQR of 2–6 lines
exceeded 1 h, the patient was given a reappointment for furthertrial on another day.
Primary outcome measure of visual success was considered tobe visual improvement of more than two lines over spectacle wear.
Table 2Dimensions of rigid gas permeable lenses in cases where fit was successful.
Base curve, based on Kreading (flat K)
On K in 3 casesSteeper to K in 73 cases (53.2%) eyes
K. Singh et al. / Contact Len
nitially fitted with rigid lenses. Soft lenses were resorted to whent least four to five trials with RGP lenses were unsuccessful due tooor fit or in cases where the RGP lens was not tolerated. Suturesrom the repaired corneal scars were removed at least two weeksrior to scheduling the contact lens fitting. Buried sutures were,owever, not disturbed unless they caused localized steepening.
The base curve of contact lens was calculated from the ker-tometric readings and final fit was determined after multiplerials. Whenever corneal distortion prevented accurate keratom-try, corneal topography was ordered to obtain detailed cornealontour information. Often in cases with gross distortion of cornea,ike bisecting scars, OrbscanTM topography failed to generate anyictorial map. Use of placido disc based topography was restricteds it had to be performed outside our centre. In cases whereorneal topography could be performed, the meridian and locationf irregular areas was demarcated and trial contact lens base curvend diameter was calculated based on Simulated (Sim) K values.
Lens fit was evaluated after in situ lens stabilization for ateast 10 min on the eye. Both dynamic and static techniques weremployed. In the dynamic technique lens movement during blin-ing, pupil coverage, and centration during primary, lateral andown gaze was evaluated. Final fit was decided after static tech-ique wherein flourescein staining was done for RGP lenses. Thearget was to get an optimum fit of central alignment with minimalo moderate edge clearance.
The rigid gas permeable lenses used in our study were fluorosil-cate with high Dk (diffusion coefficient) value of 60. Ultraviolethromatophore incorporation in contact lens was done for apha-ic and pseudophakic eyes. Initial diagnostic or trial lens wereelected from the 9.0 to 9.2 mm overall diameter (OD) range. Baseurve (BC) calculation of the trial lens was done based on formula:C = Flat K + 1/3rd of difference between flat and steep K (one-thirdf corneal astigmatism). In cases where such a lens failed to cen-re in primary and down gaze, larger diameter lenses from 9.4 mmnwards were sequentially tried and base curve was proportion-tely modified. Subsequently, based on dynamic and static fitting,ariations in base curve and/or overall lens diameters were done, tottain the best fit. Adaptation to contact lenses was defined as abil-ty to tolerate the lens without excessive watering and discomfortver a 10–20 min trial period. Soft lenses were fitted flat to K (meaneratometry reading), and subsequent fit was modified accordingo dynamic technique.
The final power of the contact lens was determined by overefraction, over the final fit. Final visual acuity with appropriateontact lens was recorded. The primary measure of success wasmprovement in visual acuity by a minimum of two lines improvementver spectacle. An alternative measure of successful visual rehabilita-ion was an improvement in vision to functional level over and above0/60 (LogMAR 0.48). This cutoff was chosen as WHO defines visionelow <6/18 (20/60) as low vision. In children with post traumaticphakia, care was taken to correct their near vision to improveheir ability to adequately perform the tasks of reading and writ-ng. Amblyopia therapy was advised wherever required in suchhildren. Data regarding indications of contact lens, location andype of opacity, lens status, number of trials required before finalt was achieved, average time taken to adapt to lens wear was alsoollected from case records.
The follow up visits were scheduled at one week, one month,hen at six monthly intervals. Lens wear time was graduallyncreased by 2 h per day in the first week till 8–10 h wear was toler-ted. Lens fit was evaluated at each follow up and complications ifny were noted. Note was made of hours of lens usage, lens surface
rregularities and deposits. Lens care was done by daily chemicalisinfection by appropriate lens solutions. In addition, periodic edg-
ng and polishing in case of RGP lenses and ultrasonic cleaning foroft lenses was instituted as and when edge roughness, scratches or
a Central opacity was defined as a scar/opacification, whose half or more size,encroached on the scotopic pupil area. As majority of our patients were cases ofpost traumatic scars, opacities purely confined to central cornea were limited.
deposits were detected on follow up. The soft lenses were changedat the one year follow up, whereas RGP lenses were usually changedafter two years of usage.
3. Results
On retrospective review of case records of patients with visualdiminution due to corneal scarring (post trauma or keratitis)referred for lens fitting, a total of 162 were identified. The baselinepatient characteristics are detailed in Table 1.
Initially RGP lenses were tried for all patients; soft contactlenses were used only if persistent decentration or intoleranceoccurred with RGP lenses. Fig. 1 shows fitting protocol used forthese patients.
The base curve of the RGP lenses required in our study rangedfrom 6.5 to 9.4. The fitting was often prolonged, requiring one toseven trials (median of 3 trials and IQR of 2–4 trials). The dimen-sions of RGP lens prescribed in this series are detailed in Table 2. Themedian time period required for fitting the final lens was 30 minwith an IQR of 20–35 min. This was time over and beyond theinitial 10–20 min required for the adaptation of the patient (firsttrial lens to stabilize on the eye). Whenever the trial time period
Flatter to K in 61 cases (44.5%) eyes
Overall diameter(8.5–10.5 mm)
8.8–9.0 mm in 28 eyes,9.1–9.5 mm in 87 eyes,9.6–10.5 mm in 22 eyes
76 K. Singh et al. / Contact Lens & Anterior Eye 36 (2013) 74– 79
ocol f
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TDc
Fig. 1. Flow chart of prot
his was achieved in 96 eyes with RGP lens use and in 17 eyes withoft lenses. Alternative outcome of success (improvement in visiono functional level over and above 20/60 (LogMAR 0.48)) could bechieved in 88 eyes with RGP lens use and in 17 eyes with soft lensesTable 3). In the group with successful RGP lens wear, corneal astig-
atism ranged from 2 to 11 dioptres, with a mean of 3.5 dioptres.ore than 32% (52 eyes) gained ≥5 lines of vision (on Snellen chart)ith the use of a contact lens. The median line improvement notedas three lines, with an IQR of two to six lines.
Patients with both central and peripheral corneal scar cases ben-fitted from use of contact lens. Primary outcome was achieved in0% of 121 eyes with central scar/opacity and in 43.6% of 39 eyes
able 3istribution of visual acuity in eyes achieving alternative outcome of success afterontact lens wear (n = 105 eyes).
Post lens fit visual acuity Snellen (LogMAR) No. of eyes
with peripheral scarring. Rigid gas permeable lenses accounted for84 and 71% of the successful fits in central and peripheral opac-ity, respectively. Two illustrative cases with central opacity andperipheral scar, fitted successfully with a RGP lens are depicted inFig. 2.
Patients presenting with aphakia and corneal scarring (forty twoeyes) required different management. In these monocular aphakes,RGP lens could be successfully fitted and centred in 25 cases, theremaining 17 patients required soft lenses. All of these cases hadastigmatism of 3 ± 2.1 (mean ± SD), ranging from 3 to 8 D. The RGPlenses were fitted for a median astigmatism of 3 with IQR between 1and 4 Dc, whereas for soft lenses the median astigmatism was 2 Dcwith IQR between 1 and 2 Dc. The base curves of the lenses werein the range of 7.2–8.2 for RGP and 8.2–9.2 for soft lenses. Amongthe aphakic group, 14 were children younger than 15 years, forwhom additional amblyopia therapy was implemented. In theseaphakic children, eight improved with and tolerated RGP lenses,rest required soft lenses. The aphakic children were usually cor-rected for distance vision and additional spectacles were prescribed
for near work. All aphakic lenses were lenticular in nature.
Soft lens could be fitted successfully in 25 eyes, however visualimprovement of 2 or more lines was seen in 17 eyes, and all of these17 were aphakes. All these cases reported a clearer vision with RGP
K. Singh et al. / Contact Lens & Anterior Eye 36 (2013) 74– 79 77
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Fig. 2. Successful fit in patient with healed kerat
enses, but fluctuating vision due to unstable RGP centration, madehem prefer the better centred soft lenses with some compromisef visual acuity.
The impact of lens fitting on the lives of these patients was dra-atic and these are best illustrated by the following two short case
ignettes of patients who successfully wore their RGP lenses forwo years.
Case 1: A 60-year-old myopic male, underwent a corneal repairor a wooden stick induced ocular trauma, his left eye, at the age of4 years. Subsequently he developed cataract in the same eye, forhich lens extraction along with intraocular lens implantation wasone. After surgery he was unable to see well in his left eye, despiteefractive correction by spectacles. This led to a compromise in hisob as a construction engineer. He presented to our centre at age 55,fter an incidental job transfer to our city. On examination, his aidedision OD was 20/20 with −3.0 D spherical correction and <20/200S (LogMAR 0.0 and 1.0, respectively). After successful contact lenst, his visual acuity improved from <20/200 to 20/40 (0.3 LogMAR)S (Fig. 3). Subsequently he could wear his lenses for more than 8 her day with frequent lubricant drops. He summed up his experi-nce as “Wish I had come here earlier, my life would have been faretter as my career performance would have been very different.”
Case 2: A 13-year-old boy had a corneal perforation in his rightye, after sustaining a fall from his bicycle at the age of 10 years.e underwent perforation repair along with lens aspiration. No
ntraocular lens could be implanted in his eye at the time of surgery.ubsequently, his school teacher noted his poor scholastic perfor-
ance and linked it to his poor vision and squinting of right eye.e advised the parents to seek medical advice. On evaluation, thehild had a visual acuity of CF 1 m OD, and 20/20 OS, with rightxotropia of 30 prism dioptres (Fig. 4). After fitting a RGP lens, his
ig. 3. Case with corneal scar, pseudophakia and IOLcapture. Case was successfully rehaine with the linear scar.
the left and peripheral corneal scar on the right.
vision improved to 20/60 (0.48 LogMAR). The child was prescribeda near add of +3 Ds, in the form of spectacles in his right eye, overthe contact lens, with which he achieved a near vision of N9. Aftersix months of use of the lens, the squinting had reduced; child wasable to read comfortably and cope up with his studies. Amblyopiatherapy with part time patching of right eye was initiated. This childhas ultimately achieved a vision of 20/40 (0.30 LogMAR) and nearvision of N6. Now, over four years later, he is off patching and useshis lens for 6–8 h a day.
In 49 eyes (41 with RGP and 8 with soft lenses), no significantvisual improvement was noted due to poor lens centration andother reasons. All these failure cases had one or more of the fol-lowing three conditions: adherent leucomas (some part of whichinvolved central 4 mm of the cornea) in 11 eyes, high astigmatismof >9 Dc (n = 13 eyes), dense central corneal opacity (n = 20 eyes),amblyopia (n = 9 eyes), retinal pathology (n = 3 eyes). The lens fittingin situ and topography of one such case is depicted in Fig. 5.
The patients were regularly monitored for development of com-plications related to contact lens usage. Ten of our cases (6.17%)developed giant papillary conjunctivitis (4 with RGP and 6 withsoft lenses) which improved after temporary discontinuation ofcontact lens usage (for 2–4 weeks) and appropriate topical med-ications. Five patients developed arcuate staining which improvedwith lubrication. Rigid gas permeable lenses were well toleratedby both children and adults, and an average 8–10 h of comfort-able wearing time was reported. All patients with successful lensfit completed the first week, first month and third month follow
up. At 6th month follow up, 15 patients (11%) in the RGP group hadlost the lens and asked for a repeat prescription. At 1 year followup, 70% (96/137) of cases with RGP lenses and all 25 soft lens userswere using their lenses on a regular basis.
bilitated with use of a RGP lens. Orbscan shows an inferior superior steepening, in
78 K. Singh et al. / Contact Lens & Anterior Eye 36 (2013) 74– 79
ong ve
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Fig. 4. Aphakic child having a full thickness 10 mm l
. Discussion
In a developing country like ours where corneal scarringccounts for more than 1/5th of the total burden of blindness [3]nd good corneas are in short supply, any suitable alternative toeratoplasty can be a welcome reprieve [11]. In pursuit of this goal,
review of the experience obtained in rehabilitating scarred corneaatients with contact lenses was done. Since soft lenses mould toorneal surface and transmit the irregular toricity of the cornea,GP lenses were the preferred modality in this series [17]. Rigid gasermeable (RGP) contact lenses nullify irregular astigmatism dueo scarring, by providing a smooth refractive surface [5,6,14]. In thistudy RGP lenses could ultimately be fitted in 83% eyes (137/162).n analysis, RGP lenses improved vision by two or more lines (pri-ary outcome of success) in 70% (96/137) cases. Soft lenses added
yield of 17 more successful cases (17 of the 25 eyes where softL was tried). With contact lenses 70% (113/162) eyes were thusenefitted. Our alternative outcome measure of attaining at leastinimal functional vision of 20/60 (LogMAR 0.48) or better above
ould be achieved in 65% cases (105/162), of which 83% (88 eyes)ere with RGP lenses.
Limited studies from the Indian subcontinent have reportedisual rehabilitation with RGP lenses in traumatized eyes wherepectacle correction failed to do so [14–16]. They have eithereviewed hard PMMA lenses or have studied a smaller numberf cases and/or had a shorter follow up. The current study high-ights experience with the better oxygen permeable fluoropolymerGP lenses. High Dk value fluoropolymer lenses are preferred forraumatized corneas which have an altered physiological milieu
nd are more vulnerable to hypoxic stress induced by lens usage18]. For aphakic and pseudophakic eyes incorporation of UV chro-
atophore in the lenses was deemed essential to prevent furtherhototoxic damage to macula [19].
ig. 5. A case with inferior adherent leucoma preventing contact lens centration. Topograor this case. Contact lens could not be fitted for this eye.
rtical corneal scar, with astigmatism of nearly 8 Dc.
On analysing the records, it was found that successful fittingover these distorted corneas dictated use of large overall diameterlenses (9.1 mm or larger) as they centred better. Over 81% of eyes inthis series could be fitted with larger OD lenses only. This was eventruer for the aphakic subgroup, where also larger OD lenses in therange of 9.2–9.8 mm were required. In the aphakic category RGPlenses were fitted for a higher astigmatism (median of 3 with IQR1–4 Dc) compared to soft lenses in aphakia (median 2, IQR 1–2 Dc).A steeper fit, which has been purported to aid centration [20], wasnot always successful in this case series. Almost a similar proportionof cases were fitted steep or flat on K reading in both phakic andaphakic subgroups.
In almost one-third of our cases (49/162, 30% cases), contactlens could not be fitted successfully due to one or more of the fol-lowing three conditions: adherent leucomas (some part of whichinvolved central 4 mm of the cornea), high astigmatism of >9 Dc,dense corneal opacity, amblyopia, retinal pathology. The experi-ence suggests that contact lens fitting should be attempted withguarded prognosis in cases with dense central opacities. In eyeswith high astigmatism (>9 dioptres) our experience was variable.Vision improved in seven eyes with use of a contact lens whereasfor 13 eyes, no such benefit was seen. Perhaps such patients may bebetter suited for other types of lenses like reverse geometry lenses,scleral lenses or hybrid lenses. Such lenses succeed by eliminatinglid–lens interactions [21,22]. Unavailability and non affordabilityof such lenses precluded their use at in this case series.
In this study aphakic contact lenses were required in 26%(42/162) eyes. The role of contact lenses in treatment of unilateralaphakia has been validated by various studies [23–25]. Contact
lenses restore binocular vision in such situations, by reducing theamount of unilateral magnification compared to spectacles. Inafflicted children restoration of stereopsis can subsequently betried, once binocularity is achieved. In the aphakic group, fourteen
phy depicts an astigmatism of 17 Dc. Orbscan could not generate any pictorial map
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atients were younger than 15 years and required additionalmblyopia therapy. Importantly all cases who benefitted with softontact lenses had coexistent aphakia. Vision improvement withoft lenses in these corneal scar cases may primarily be due tophakic refractive correction and not due to astigmatism control.
Contrary to popular belief held by contact lens fitters RGP lensesere well tolerated by children in this series. Twenty-eight childrenere fitted with RGP lens and they adapted well over time to these
enses. The properties of RGP such as high oxygen permeability,ow bacterial and protein adherence make them a safer albeit lessomfortable option for children [26,27]. The quantum of visual gainas significant enough with RGP lenses in these children, for them
o happily adapt to the initial discomfort.Over a two-year follow up, 41 patients became irregular with use
f their lenses. They would only use them intermittently for socialccasions, for few hours of the week. The reasons cited for inade-uate usage were: inability to afford replacements for frequent lens
oss, difficulty in lens care and cost of replacing solutions/lens. Thenderlying reason for inconsistent acceptance may lie in the profilef the reported patients as most of them were low wage unskilledaily wagers with less demanding visual requirements.
. Conclusions
This study documents that contact lenses, primarily rigid gasermeable lenses, are an effective means of visual rehabilitation inatients with corneal opacity/scars, with significant improvement
n vision over that with spectacles. Patients with high astigmatismue to adherent leucomas may not benefit as well as other casesith corneal scarring. The successful practice of employing contact
enses in scarred corneas reduces the dependence on keratoplastyhich is a welcome step in a country where demand for donor
ornea far outstrips the supply. The post surgical course of a graftedye requires meticulous medical care to prevent complications likeejection, infection and glaucoma. Even post keratoplasty, contactenses maybe required to manage the suture induced astigmatism.hus, contact lens rehabilitation for scarred corneas destined foreratoplasty is advantageous in all aspects, especially so in regionsith inequitable access to medical care.
onflict of interest statement
The authors declare that they have no financial involvement oronflict of interest with the subject of this study.
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