What is Amblyopia?
When a patient has sub-normal vision in an eye that is anatomically normal, he is said to have Amblyopia. This means that even on complete examination, no such factor can be found that can account for the decreased vision.
Any factor in early childhood that hampers or interferes with the vision of the child for long can lead to Amblyopia. So, causes can be numerous and varied.
- Childhood cataracts left un-operated for long
- Droopy upper eyelids (Ptosis)
- Dense opacities in the cornea
- Moderate to high refractive errors left uncorrected
- Large differences in the refraction (power) of the two eyes
Due to any of the factors mentioned above, the vision of the child gets disturbed. As a compensatory mechanism to obtain clearer vision, the brain, instead of fusing images received from both eyes, suppresses the one received from the affected eye. This, ultimately, leads to Amblyopia in the weaker eye. When there is deprivation of the visual stimulus on both sides, Amblyopia can be bilateral.
If Amblyopia is detected early, appropriate therapy can help reverse the condition. However, if ignored, Amblyopia becomes permanent so that vision does not improve by any means.
First, the factors predisposing to Amblyopia need to be addressed. Cataracts may require extraction, ptosis is surgically corrected and glasses are used to correct refractive errors. The child may then be advised daily exercises on a special instrument, the synoptophore (pleoptics), that help to break Amblyopia.
At home, parents can contribute to the treatment by making the child use the affected eye. This can be done by covering or ‘patching’ the normal eye. Patching can be done for a few hours everyday or as advised by the ophthalmologist. Also, the child may be advised to do eye exercises for stimulation of vision, like reading, threading a needle or other fine work. It is important for the child and his parents to realize that Amblyopia treatment requires months to years of consistent efforts before adequate results can be obtained.