What is Amblyopia Secondary to Anisometropia?
When the eyes have a significantly different refractive error or eyeglass prescription, one image in one of the eyes will not be in focus on the retina. When the child is young, the brain and eyes are developing the vision system. If there is not a clear image focused on the retina in each eye the vision system in that eye and portion of the brain will not develop properly resulting in a loss of vision. The amount of loss will be determined by the size of difference between the two eyes.
What Causes Amblyopia Secondary to Anisometropia?
The size and shape of the eye determines whether an eye is nearsighted, farsighted, or has astigmatism. If the is a large enough difference in the size and shape between the two eyes, then one eye will have blurred vision will amblyopia. The eye that is more farsighted almost always develops the amblyopia.
Incidence of Amblyopia Secondary to Anisometropia
Approximately two to three percent of children develop amblyopia. Anywhere from thirty to fifty percent of amblyopia is secondary to anisometropia.
Diagnosing Amblyopia Secondary to Anisometropia
A thorough comprehensive eye exam is all that is needed in order to diagnose the anisometropia and loss of vision in one eye. Other testing is not needed unless the severity of the vision loss and the degree of amblyopia do not match.
Treatment and Management of Anisometropic Amblyopia
Treatment of the anisometropia is the first priority in treatment of the amblyopia. The proper eyeglasses may be all that is needed to treat the amblyopia.
If the amblyopia does not resolve with wearing glasses, patching the good eye may be necessary. The more severe amblyopic children will need to be patched in many cases. When patching, the younger the child the more often they need to be seen to monitor their eyes. If the good eye is patched too long it can develop amblyopia.
Atropine can be tried to blur the vision in the good eye. Atropine is an eye drop that paralyzes the focusing in the eye.
Neutral Density Filter
Neutral density filters have been used with success in treating amblyopia in many children.
In general, the younger the child is started on treatment the better the results. If the amblyopia is less, the results are improved. It is important to make sure that each child has their vision tested either by their pediatrician or eye doctor.