What causes adult amblyopia and what is the treatment?

Amblyopia is a general term meaning impaired vision.

Amblyopia ex anopsia is visual loss in children, which, if not treated at an early age, becomes permanent. Children do not complain of it and adults usually are unaware of its presence unless they cover one eye or have an eye test, general physical exam, driver's license exam, etc. The eyes themselves are normal to examination but fail to develop normal vision because they are not stimulated in early childhood. This can occur because of a drooping eyelid, cataract or tumor blocking the entry of light into the eye, a large difference in refractive error (need for eyeglass correction) between the two eyes, or strabismus (failure of the two eyes to align on the same target simultaneously). In the latter case, the brain initially sees double, which is annoying, and learns to suppress one image for comfort. The net result is that the vision loss eventually becomes permanent.

Treatment is directed to the cause and may be surgical removal of the obstruction, correction of the drooping eyelid, cataract surgery, eyeglasses, contact lenses, etc. The earlier the treatment is begun, the faster the correction. Often the child has to wear an eye patch on the GOOD eye, or use eye drops to blur it, forcing use of the eye with the decreased vision. We used to believe that this treatment had to be done by age seven years, but often can work in older children. Pleoptics and flashing light treatments have no proven value. Laser vision correction has been used to correct the refractive errors, but patching is still necessary.

The important message here is that no child is too young to have an eye examination, and parents should consult an ophthalmologist promptly if they notice or suspect anything or if there is a family history of amblyopia.


This question was originally answered on Sept. 5, 2012.