1. Diagnosis & Treatment of
Childhood Amblyopia
Dr Milind M Sabnis.
Prof & HOD Ophthalmology .
D Y Patil Medical College,Kolhapur.
2. Definition
• Unilateral or bilateral reduction in the BCA
caused by form vision deprivation and/or
abnormal binocular interaction without
visible organic cause responsible for its
vision loss.
• Difference of 2 or more lines between
normal and amblyopic eye for unilateral
and BCA < 20/40 for bilateral amblyopia is
necessary.
3. • Epidemiology
- 1-5% of population in developed countries
- In India, affects 1-4% of Children
- Author Series 3-4 per 80 OPD patients &
30-40% in strabismus and amblyopic
clinic.
- Occurs 4 times frequently in premature &
6 times common with delayed milestones
4. • Pathophysiology
- Basic work done by HUBEL & WIESEL,
“There are losses in the number of cells
responsive to deprived eye, loss of
binocularly responsive cells, shrinkage of
cell in LGN Laminae serving the deprived
eye and significant abnormality in the
responsive qualities of the cells.
- Imaging confirms abnormality in area 6 of
Human Cortex.
5. Diagnosis
• Is by Routine Screening while checking
VA between 3-5 years.
• Critical period – begins at 4 Months, peaks
at 2 years, gets down by 5 years & than
slowly declines and ceases at 12 years.
• Deprivation below 3 months produces
significant reduction and between 3-8
years less and responds better to therapy.
6. Clinical Features
1. Confirm Dimness of Vision (DOV) – Decreased
foveal acuity, 3 logmar lines difference
between 2 eyes.
2. VA in Children more than 3 Years –tested on
Snellen’s Chart. Between 2-3 years E-Charts,
Landolt’s ring or pictures. In Infants, Fixation
preference and in pre-verbal child – VEP or
Optokinetic Nystagmus
3. If Nystagmus requires blurring of other eye by
+ 6 D Lens during Vision Testing
4. Stereoacuity – 2-Penci Test & Titmus Fly Test
7. 5. Fixation Reflex Presence of alternate fixation
rules out Amblyopia.
Child will not resist if Amblyopic eye is covered
(These techniques are not useful in Microtropia
and Orthophoria).
6. Crowding Phenomena Better VA for Single
Letter (Sheridan Gardiner Test).
7. Effect of Neutral Density Filter – In Normal Eye
Vision is reduced but in Amblyopic Eye does not
decrease but may improve.
8. Colour Vision Normal. Only in Dense
Amblyopia defective due to Eccentric Fixation.
8. 9. Contrast Sensitivity Strabismic &
Anisometropic types show loss
10. Accommodation Normal or reduced in some
but vision for near is better than distance
11. Fixation Pattern Eccentric Fixation in 25-
90% of patients.
12. VEP – Visual Evoked Potential Grating &
Checker board stimulus viewing shows reduction
in Amplitude and Normal or slightly prolonged
latency
13. Miscellaneous Features May have RAPD,
Normal Vision in Dim Light, Nystagmus,
Abnormal Binocular Vision, ARC.
9.
10.
11.
12. Amblyopiogenic Factors
• Search for these is very important.
• Like Unilateral Congenital Cataract, Ptosis,
Media Opacities, also bilateral cataract and
opacities.
• Hypermetropia more than 3-5D & Astigmatism
more than 1.5
• Presence of Microtropia and small angle
Esodeviations.
• Two Conditions may co-exists Organic
Disease & Amblyopia [Trial of 3-4 weeks
occlusion may be given in these cases]
13. A Case of Strabismic
Amblyopia
A Case of Anisometropic &
Strabismic Amblyopia
14. Classification of Amblyopia
1. Strabismic – Chavasse called amblyopia of
arrest and amblyopia of extinction which is
now outdated concept.
2. Anisometropic Diagnosis may be delayed
as eyes are straight
3. Isometropic Hypermetropia more than 6 D.
4. Meridional Astigmatism > 1.5
5. Visual Deprivation Third Common Type,
Most damaging & Difficult to treat & was also
called as “Amblyopia ex Anopsia”.
6. Organic Amblyopia due to cone deficiency,
Nystagmus, Hysterical, Functional & Retinal
Haemorrhages.
15. Rx of Amblyopia
• Treat as early as possible.
• Either before or with therapy of amblyopia treat
refractory error and correctable ocular anomaly.
• Record a) Age of Onset; b) Interval between Onset &
Presentation; c) Education & Motivation of Parents; d)
History & Prior Treatment; e) Vision recording Use
same charts
• Proper Cycloplegic Refraction & Prescription of Glasses;
Fundus Exm, Fixation Pattern & Preferecne
• Apply full time occlusion as first line therapy; if non
compliant only than ‘Penalization’. Supplementation by
Levodopa in severe cases
• Goal of Rx To Eliminate Eccentric Fixation &
Localization as well as development of foveal fixation.
16. Refraction Correction
• Treat Ametropia on objective and not
subjective basis though initially
uncomfortable
• Correction helps alone in 30% cases.
• Use 1% Atropine below 7 years & 1%
Cyclopentolate in older Children.
• Some follow refraction correction not
improving amblyopia for 4 months by
occlusion treatment.
17. Occlusion
• Is treatment of Amblyopia since 1722.
• Best achieved by adhesive skin patch.
• Success rate – 33-92% & might improve
Strabismus
• Can be started at any age
18. Types of Occlusion
1. Total or Partial –
2. Conventional or Inverse –
3. Fulltime or Part time –
4. Continual
21. • Frequent follow-up is essential as occlusion
amblyopia is a problem
• Rule is 1 week for every year of child
• If fixation is not improved in 3 months, occlusion
should be stopped.
• At follow-up, test vision both eyes, fixation
pattern, presence of occlusion amblyopia
[Indicates that patient has potential for equal
vision in both eyes]
• Occlusion is stopped when vision becomes
equal in both eyes, when true alteration in
fixation and no improvement in vision in 3-6
months.
• Follow-up after completion till 12 year of age
• Maintenance on either part-time or partial
occlusion or penalization.
23. • “OCCLUSION IS NOT ADVISABLE IN
ANISOMETROPIC AMBLYOPIA”
• Prognostic Consideration in Amblyopia
1. Age; 2. Type of Amblyopia; 3. Treatment
Duration; 4. Pre-teratment Vision; 5. Type of
Occlusion; 6. Type of Fixation; 7. Type of
Occluder; 8. Near Vision exercises; 9. Patient
Compliance; 10. Presence of Astigmatism; 11.
Method of termination of treatment; 12.
Previous Treatment; 13. Refraction Correction
• Inverse Occlusion Only used to familiarize
the occlusion
24. Penalization by using Cycloplegia
• Cosmetically acceptable but does not
inhibit binocular abnormal interaction
• Indicated in moderate amblyopia in un
cooperative patients, anisometric
amblyopia, maintenance treatment,
occlusion failure or Nystagmus
• Role of near activities is gaining
importance in treatment of Amblyopia
along with occlusion
25. Other Modalities of Rx
1. LASIK – For Anisometropia
2. Pleoptics To stimulate Macula in Eccentric Fixation.
Only indication is co operative and intelligent child
more than 6 years having eccentric fixation and is
contraindicated above 8 years because of risk of
inducing Diplopia.
3. Cam-Satmulator Cambell & Coworkers. Disc
rotation 1 per minute to provide different stimulation to
variety of brain cells. 7 disc of various spatial are used.
Test is of 7 minuets.
27. Pharmacological Treatment
• Tried with strychnine, Vitamine B, Barbiturate,
Ethanol but Levodopa & Citicoline are used now
a days.
• Levodopa of the precursor of Dopamine, a
neurotransmitter known to influence both retinal
and cortical level of visual system
• Levodopa either extents or reactivates visual
system sensitive period of neural plasticity and
hence its role in Amblyopia
28. • Effects of Levodopa
- Increased vision after 1 week in 70% patients and
with 3 week treatment effect persist for 2 months
- Dose: 0.48 mg / kg for 3 weeks [Minimal Side
Effects]
- Increased contrast sensitivity and decreased
binocular suppression
- Effect is enhanced by occlusion
- Levodopa is promising agent in Augmenting
conventional occlusion, speeding recovery,
decreasing cost but side effects like diarrhoea,
abdominal pain, mood changes, decrease resp. rate
& heart rate and hallucinations are to be noted.
- CITICOLIN – Dose: 1 Gram / Day i.m. for 15 days
but is not available in India
29. Special situations in Amblyopia
1. Surgery first or amblyopia treatment first?
2. Amblyopia with eccentric fixation
3. Amblyopia with Nystagmus
4. Refractive Amblyopia
5. Unilateral Aphakic Patient
Age Limit for treatment of amblyopia was consider
8 years but recent report say it is effective in
older child.
30. Conclusions
1. Full time occlusion is preferred treatment
2. Levodopa may be consider as an adjunctive treatment
3. Proper optical correction is powerful treatment of amblyopia
4. Near vision activities are becoming popular in treatment.
5. LASIK should be tried at last resort in Anisometropic Amblyopia
6. Pleoptics * Cam-Stimulators are out dated modalities
7. Requires multi-disciplinary approach – Paediatritian, GP, Teacher
& parent
“SO LET US JOIN TO MAKE INDIA AMBLYOPIA FREE”
