Retinoscopy

transcript

Presentor:-Dr.Pushkar Dhir

Moderator :-Dr. Jyoti Puri

RETINOSCOPY

OPD -EXPERIENCE

• Far Point (FP) is the farthest point at which objects can be seen clearly by the eye.

• So in this patient d farthest point came out to be approx .4 mtrs.

• i.e she can see all d things vch r <4metres.

• To avoid this arbitrary n cumbersome method of finding refractive power ---> illumination reflexes were studeid in emmetropic and eye n correlated with the refraction power.

• Power= Diopteric power – cycloplegic – 1/working distance

ASTIGMATIC FAN

OBJECTIVE(what is done by the clinician)

SUBJECTIVE(refininng obj.refractn to maximize VA)

AUTO.REF

DUOCHROME TEST

ABERROMETRYKERATOMETRYRETINOSCOPY

REFRACTION

BINOCULAR BALANCING

DRY :- Without CycloplegicsWET:- With CycloplegicsDYNAMIC:- With Accomodation

• Started by Bownman in 1859

• Also known as:- Shadow test Skiascopy Pupilloscopy Korescopy

• The only way to assess the refractive error in infants, small children, illiterates, uncooperative patients with speech loss patients who speak a different language.

•Introduced quantitative refraction test.•Made possible to measure exact amount of refractive error using lenses. •Termed retinoscopie.

OPTICS OF RETINOSCOPY

ILLUMINATIONSTAGE

REFLEX STAGE

PROJECTIONSTAGE

Fundal area illuminated by the light reflected into the

patient’s eye .

Illuminated area serves as an OBJECT

Lights Rays reflected back from Fundus -> form reflex

shadow in pupillary area

Pupillary shadow observed by the examinar by aligning

his/her eyes

Advantages of streak -Undilated pupilMore accurateAstigmatism Axis of the astigmatism

D GOOD OLD DAYZZ

DR.SHASHI

APHAKIA- DULL GLOW

HIGH MYOPIA- STREAK NOT VISIBLE

VIDEO(on u tube)

TYPES OF RETINOSCOPES

Lister Reflecting Retinoscope

Priestley Smith ReflectingRetinoscope

Self Illuminating Retinoscope

Spot RetinoscopeStreak retinoscope

• Time to charge ur laptop

Done in long, darkened room, to aid in relaxation of accommodation The patient is made to sit at a distance of 1mt from the examiner Working distance of 2/3 mt is more convenient. Light is thrown in the patient’s eye who is instructed to look at a far point (to relax accomodation) If a cycloplegic used (wet retinoscopy) patient can look directly into the light & refraction

assessed along the actual visual axis. Observe a red reflex in the pupillary area of the patient. Retinoscope is moved in the horizontal and vertical meridia, keeping a watch on the red reflex

which also moves when the retinoscope is moved.

~ 50 cms

Movement(with working distance at 1 metre)

Against

Myopia >1D

Emmetropia

Hypermetropia

Myopia

No movement

Myopia =1D

WHAT TO ASSES?

Size, Speed & Brilliance

Small (Narrow) Fast & Brighter

Low Refractive Error

Large (Wide) Slow & Dim (Faint Glow)

High Refractive Error

Hazy Media

DEMONSTARTIONhttp://www.eyedocs.co.uk/ophthalmology-learning/articles/optics-and-refraction/1508-retinoscopy-simulator

Neutralization of red reflex :

in Streak Retinoscope

a. Neutralization - the band of red reflex moves ‘with’

or ‘against’ the movement of the band of light from retinoscope

- in simple spherical errors, at neutralization the band shaped reflex disappears and pupil appears completely illuminated.

Finding the cylindrical

i) - break in alignment is observed when the streak is not parallel to one of the principal meridia(horizontal and

vertical).

- the axis, can be determined by rotating the streak until the

break disappears.

(ii) - width of the streak varies as it is rotated around the correct axis. It appears narrowest when the streak aligns with the true axis.

(iii)- Intensity of reflex is brighter when streak aligns with true axis.(iv)- Skewing (oblique motion of the streak reflex)

f. End point of neutralization - width of reflex widens progressively as the

neutralization is achieved, and at the end point, streak disappears and the pupil appears completely illuminated or completely dark

WET RETINOSCOPY : CYCLOPLEGICS In Retinoscopy

• Paralysis of Accomodation + Dilation of Pupil.

• Used in young children and hypermetropes where it is suspected that the accommodation is abnormally active and hinders exact retinoscopy.

• Mydriatics to be used cautiously in adults with shallow anterior chamber

WET RETINsc

<5 yrs 5-8 yrs 8-20 yrs MYDRIATIC >CYCLOPLEGIC -do-

DOSE- TDS X 3DAYS

1DROP X 10 MIN X6 TIMES

1 DROP X 15 MIN X 6

TIMEES1DROP X15MIN

X3 TIMES -do-

PEAK EFFECT

2/3 DAYS 60-90MINS 80-90 MINS 20-40 MINS -do-

RETINO TIME- 4TH DAY

AFTER 90 MIN OF 1ST

DROPAFTER 40 MINS -do-

EFFECT DURTN

10-20DAYS 48-72 HRS 6-18 HRS 4-6 HRS -do-

PMT- AFTR 3 WKS

AFTER 3 DAYS

8 HOURS/NEXT DAY -do-

CORRECTION-

1D 0.5 D 0.75 D XXX XXX

0.5%,1%

Beta Kitne Der

Lagegi!!!

Reflex Hi

nahi dikh

NEED DR LIKH KAR BHEJ

DETA HUN

PROBLEMS IN RETINOSCOPY

PROBLEMS CAUSE SOULTION

RED REFLEX NOT VISIBLE1.SMALL PUPIL2.HAZY MEDIA

3.APHAKIA/HIGH MYOPIA

1.TRY MYDRIATICS +CYCLOPLEGICS COMBINATION

2.REDUCE WORKING DISTANCE + BRIGHT SOURCE OF LIGHT

3.TRY LENSES OF HIGH POWER+/- 7D, IF STILL NOT ,GO HIGHER.

CHANGING RETINOSCOPIC FINDINGS

ACCOMODATION USED BY PATIENTS

FOGGING- -- PLACE A LENS SUCH THAT VISION BECOMES 6/60 &

THEN START NEUTRALISING.V R ACTUALLY TYRING D CILIARY

MUSCLES BY DOING DIS.

SCISSOR SHADOWS

MIXED ABERRATION E.G KERATOCONUS

OPT FOR ONE SLIT & ADD LENSES , SLOWLY SLIT BECOMES

EQUAL,THAT’S IT.(DIRTY REFRACTION)

POSITIVE SPHERICAL

ABERRATIONS

NEGATIVE SPHERICAL ABERRATION

Uneven wavefront (aKA“optical aberrations”) can be because of asphericalcorneal, lens & retina or uneven thickness of tear film

MEASURING OPTICAL ABERRATIONS

• Shack-Hartmann (SH) aberrometer measures wavefront objectivel

Subjective Refraction• Power of spherical and cylindrical

refraction refined based on patient response

• General rule: Maximum Plus for Maximum Visual Acuity.

• Duochrome test: Based on chromatic aberration; red is

focused more hyperopically than green; yellow is focused on retina

• Letters on both red and green background should appear equally clear

SUBJECTIVE REFRACTION

1. Subjective verification of refraction By Trial & Error technqiue Astigmatic Dial technique

2. Subjective refinement of refraction JCC Astigmatic Fan test

• Combination of two sphero-cylinders: -0.25D sphere & +0.50D cylinders with axes at right angles.

• To determine end-point of magnitude, place JCC with axis parallel to the axis of the cylindrical prescription.

Jacksons Cross Cylinder

Astigmatic Dial Technique

• Fog the eye

• Patient asked to look & identify darkest &sharpest line in astigmatic dial.

• Add minus cylinder of progressively increasing power

• Axis perpendicular to the darkest & sharpest line, till all lines are clear.

• Revert back fogging.

REFERENCES• http://www.slideshare.net/meikocat/Refraction• http://www.eyedocs.co.uk/ophthalmology-learning/articles/opti

cs-and-refraction/1508-retinoscopy-simulator• http://retinoscopy.blogspot.in/

• http://books.google.co.in/books?id=6I6JeDWonhQC&pg=PA2&lpg=PA2&dq=RETINOSCOPY+WITH+PLANE+MIRROR&source=bl&ots=owV9UpZtAO&sig=ku6SiYptvYp_qlEbBi-g2YW7izM&hl=en&sa=X&ei=-mypU8K5MdeUuASBi4HIDw&ved=0CEkQ6AEwCg#v=onepage&q=RETINOSCOPY%20WITH%20PLANE%20MIRROR&f=false

• http://www.college-optometrists.org/en/college/museyeum/online_exhibitions/optical_instruments/retinoscopes.cfm

Had dat Referee had 6/6 refined vision , Argentina would never hav won 1986 FIFA WORLD CUP!!!!!

• THANK YOU EVERYONE FOR PATIENTLY LISTENING TO THIS SEMINAR.

• For feedbacks & brickbats plz mail at• ykush@yahoo.co.in./drdhir2014@gmail.com

HAND OF GOD

Retinoscopy

Education