Amblyopia and its Management in Congenital Cataract

1. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
AMBLYOPIA AND ITS MANAGEMENT IN
CONGENITAL CATARACT
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Rabindra Adhikary
ravinems@iom.edu.np

2. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
BIBLIOGRAPHY
• Pediatric Ophthalmology and Strabismus AAO Series
• Myron Yanoff Ophthalmology 2nd
Edition
• Practice of Refraction Duke Elder
• Clinical Management of Strabismus Caloroso
• Strabismus Himadri Datta
• Relationship between anisometropic amblyopia and
binocularity Niraj D Joshi
• Various articles from the internet
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3. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
DEFINITION
• Amblyopia is a unilateral or bilateral reduction
in visual acuity caused by form deprivation
and/or abnormal binocular interaction for
which no organic causes can be detected and
which in appropriate cases is reversible by
therapeutic measures.
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4. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Greek word
Amblyos = Dull or Blunt
Opia = Vision (Lazy Eye)
• Hippocratus : weak vision
• Plenk : weak vision without visible damage
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5. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Major cause of visual deficit
• Incidence of amblyopia 2-2.5 % of
population (1.3 % of Nepali Population)
• 4 times more prevalent in LBW and premature
babies
• 6 times more in children with delayed
milestones and CNS disorders
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6. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
CLASSIFICATION
• 1-Strabismus
• 2-Anisometropia
a-Anisohypermetropia
b-Anisomyopia
• 3-Isoametropia
• 4-Form vision deprivation (amblyopia ex anopsia)-
unilateral/bilateral
a-Complete ptosis, media opacities (corneal, lental),
unilateral occlusion and prolonged atropinization
b-Uncorrected bilateral high hypermetropia
c-Astigmatism
d-Nystagmus
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7. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
TYPES OF AMBLYOPIA FOUND IN
CONGENITAL CATARACT
• Strabismic Amblyopia
Amblyopia in patients who have
strabismus occurs only if one eye is preferred
for fixation; free alternation of fixation
between the eyes is incompatible with the
development of strabismic amblyopia.
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8. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Anisometric Amblyopia
Develops when unequal refractive error in
two eyes causes the image on one retina to be
chronically defocused.
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9. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Isoametropic Amblyopia
Is bilateral and associated with
approximately equally large hyperopic,
myopic, or astigmatic errors or combination of
these.
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10. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Deprivation Amblyopia (Amblyopia Ex
Anopsia)
Amblyopia that results from a media
opacity of early onset in one or both eyes.
It is the least common, most damaging and most
difficult to treat.
May be irreversible beyond 6-12 years of age
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11. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
DEPTH OF AMBLYOPIA
Visual acuityVisual acuity
shallowshallow Less than 6/18Less than 6/18
moderatemoderate 6/18 - 6/366/18 - 6/36
deepdeep 6/60 or worse6/60 or worse
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12. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
DIAGNOSIS
• Detailed history
Infections during ante natal period
Type of delivery
Birth weight
Post natal infections
Congenital
Traumatic
Metabolic disorders
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13. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
DIAGNOSIS CONT.
• Visual acuity- A difference in visual acuity between
the two eyes of at least two lines of the chart is
indicative of amblyopia.
• Visual acuity should be measured both by using a
normal chart (line acuity) and by presenting one
symbol at a time. (letter acuity)
• In amblyopia there is a discrepancy between the
results of these two types of measurements which is
absent in other organic pathologies. (CROWDING
PHENOMENA)
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14. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
DIAGNOSIS CONT.
• Pattern of fixation.
A-the capability of an eye to take up and
maintain fixation. An eye with dense unilateral
amblyopia cannot fix.
B-Fixation pattern. It is useful to find out
whether fixation is central and steady or
eccentric and/or wavering.
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15. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Slit lamp examination
To r/o media opacities
lid
cornea
lens
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16. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Refraction
• Cyclorefraction
• retinoscopy
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17. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
TREATMENT STRATEGY
• - Clear visual axis & proper correction of
refractive errors
• -To enhance cortical processing of visual input
from the amblyopic eye (Occlusion)
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18. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
TYPES OF TREATMENT
1-Penalization
Atropine treatment of sound eye with
distance correction may encourage use of
amblyopic eye for near tasks
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19. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
TREATMENT CONT.
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2-Game therapy2-Game therapy
Active visual involvement of theActive visual involvement of the
amblyopic eye is encouragedamblyopic eye is encouraged
3-Oral levodopa and carbidopa3-Oral levodopa and carbidopa
Low doses of levodopa alone andLow doses of levodopa alone and
together with carbidopa have been showntogether with carbidopa have been shown
to augment the effect of patchingto augment the effect of patching

20. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
TREATMENT CONT.
4-Pleoptics
Involves bleaching the peripheral retina
via a powerful modified direct
ophthalmoscope and stimulation of the fovea.
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21. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
TREATMENT CONT.
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5-CAM vision stimulator5-CAM vision stimulator
The CAM vision stimulator is a discThe CAM vision stimulator is a disc
imprinted with bar gratings; discs ofimprinted with bar gratings; discs of
varying spatial frequencies are rotatedvarying spatial frequencies are rotated
slowly before the amblyopic eye, with theslowly before the amblyopic eye, with the
sound eye occluded.sound eye occluded.

22. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
TREATMENT CONT.
6- Sectors
This method involves masking portions of
the glasses.
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23. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
7-OCCLUSION THERAPY
• A patch over the better-sighted eye remains
the mainstay of active treatment of
amblyopia, even in patients who have
eccentric fixation.
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24. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Cataracts capable of producing amblyopia
must be operated at the earliest.
• Refractive correction for aphakia following
cataract surgery must be given promptly. The
refractive error should be treated first
• Optimal prescription for amblyopic eye should
correct the full refractive error as determined
by cycloplegia
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25. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
THE MORE COMPLETELY THE LIGHT IS
ELIMINATED, THE MORE EFFECTIVE THE
PATCH
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27. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Occlusion of the fixating eye removes
inhibitory stimuli to the amblyopic eye. It can
be either total or part time.
• To prevent occlusion amblyopia of the sound
eye alternate occlusion should be done.
• Visual acuity of both eyes should be
monitored at regular intervals
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28. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
OCCLUSION REGIME
AGE OF THEAGE OF THE
CHILDCHILD
AMBLYOPIC EYE: BETTER EYEAMBLYOPIC EYE: BETTER EYE
1 YEAR1 YEAR
2 YEARS2 YEARS
3 YEARS3 YEARS
4 YEARS4 YEARS
5 YEARS5 YEARS
6 YEARS AND6 YEARS AND
ABOVEABOVE
1:11:1
1:21:2
1:31:3
1:41:4
1:51:5
1:61:6
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29. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Overtreatment may lead to “occlusion
amblyopia” in the originally better eye.
• Close monitoring is needed particularly in a
young child
• Recent studies have shown that part time
occlusion is as effective as total occlusion.
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30. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
OCCLUSION THERAPY(PATCHING)
CONT.
• FULL TIME
Advantages;
1- more rapid amblyopia reversal (unproved)
2-better acuity results (unproved)
Disadvantages;
1-risk of iatrogenic amblyopia
2-risk of development of strabismus
3-more cosmetic deformity
4-poorly tolerated during school hours
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31. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
OCCLUSION
• PART TME
Advantages;
1-iatrogenic amblyopia rarely occurs
2-strabismus rarely decompensate
3-less cosmetic deformity
4-can occlude outside of school hours
Disadvantages
1-slower amblyopia reversal(?)
2-worse acuity results (not proven)
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32. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
SIDE EFFECTS OF OCCLUSION
1-Skin irritation and allergy
2-Risk of accidents with patch on
3-Precipitation of strabismus
4-Occlusion induced amblyopia
5-Psycho-social aspects
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33. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
CRITERIA FOR VISUAL IMPROVEMENT
1. Isoacuity between the good and the
previously amblyopic eye
2. Equal speed of reading for both eyes
3. Free alteration of fixation ensures that a
cure has been obtained
4. Isoaccommodation is achieved when a cure
is obtained and free alteration of fixation is
reached.
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34. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
• Recurrence may occur in about 50% of
patients when amblyopia treatment is
discontinued after fully or partially successful
completion of occlusion therapy
• This can be reversed with renewed
therapeutic effort.
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35. AMBLYOPIA AND ITS MANAGEMENTAMBLYOPIA AND ITS MANAGEMENT
CONCLUSION
• Amblyopia treatment is a team effort
• Success depends on
Pts compliance
Parental care
Optometrist/ Ophthalmologist
• Severity of amblyopia
• Age of initiation of therapy
• Follow up
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