Amblyopia

1. AAMMBBLLYYOOPPIIAA
Dr. Christina Samuel

2. It implies a partial loss of sight in one or
both eyes For which no cause can be
detected by physical examination of the
eye

3. PPAATTHHOOPPHHYYSSIIOOLLOOGGYY
Amblyopia is believed to result from
inadequate foveal or peripheral retinal
stimulation and/or abnormal binocular
interaction that causes different visual
input from the foveae.

4. CCllaassssiiffiiccaattiioonn
Strabismic
Anisometropic
Stimulus deprivation
Bilateral ametropic
Meridional

5. Strabismic :
results from prolonged uniocular
suppression in children with uniocular
squint who fixate with the normal eye.

6. Anisometropic:
Caused by difference in refractive error
between eyes….one eye having a higher
refractive error than the other eye.

7. Stimulus deprivation:
Results from vision deprivation.
When one eye is totally excluded from
seeing early in life as in congenital
cataract or corneal opacities or ptosis
covering the pupil.

8. Bilateral ametropic:
Results from high symmetrical refractive
errors, usually hypermetropia.

9. Meridional:
Results from image blur in one meridian.
It can be unilateral or bilateral and is
caused by uncorrected astigmatism
usually >1D persisting beyond the
period of emmetropization in infancy.

10. DDiiaaggnnoossiiss
Clinical features
VA:
1. Difference of 2 lines between 2 eyes
2. Crowding phenomenon: Single letter
acuity better than linear acuity
• Color vision: Abnormal
• Contrast sensitivity: Decreased
• Stereoacuity: Decreased
• ? RAPD

11. TTrreeaattmmeenntt
Treatment of amblyopia involves the
following steps:
Eliminating (if possible) any obstacle to
vision such as a cataract
Correcting refractive error
Forcing use of the poorer eye by limiting
use of the better eye.

12. CCaattaarraacctt rreemmoovvaall
Cataracts capable of producing amblyopia
require surgery without delay.
Removal of significant congenital lens
opacities during the first 2-3 months of life
is necessary for optimal recovery of vision.
In symmetrical bilateral cases, the interval
between operations on the first and second
eyes should be no more than 1-2 weeks.
Acutely developing severe traumatic
cataracts in children younger than 6 years
should be removed within a few weeks of
injury, if possible.

13. RReeffrraaccttiivvee ccoorrrreeccttiioonn
In generally, optical prescription for
amblyopic eyes should correct the full
refractive error as determined with
cycloplegic.

14. OOcccclluussiioonn
It is the most powerful means of treating
of amblyopia by enforced use of the
defective eye.
Occlusion therapy
 Age to initiate treatment:
– The earlier the better
– After 6-7yrs of age, slow improvement
– Full time vs part time

15. Methods of occlusion:
1. Direct patch over skin: Best
(completely blocks stimulus from sound
eye)
2. Patch over back surface of glasses
3. Occlusive contact lens for very
uncooperative children

17. PPeennaalliizzaattiioonn::
A cycloplegic agent (usually atropine 1%
or homatropine 5% ) once daily to the
better eye
This form of treatment has recently been
demonstrated to be as effective as
patching for mild to moderate amblyopia.

18.  The time required for completion of
treatment depends on the following:
1. Degree of amblyopia
2. Choice of therapeutic approach
3. Compliance with the prescribed
regimen
4. Age of the patient

19. TTHHAANNKK YYOOUU