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I had some questions about amblyopia. My left eye sees completely and my right eye sees only 10 to 20 percent. I had a misalignment operation at the age of 6, and then a laser operation for hyperopia at the age of 8, but it didn't correct anything. My right eye used to turn inward and now it turns slightly outward; even more so I'm when tired. I've read about vision therapy and wondered whether this could be a possible cure. I am now 31 years old. Would there be any chance for my eye to gain complete vision again?
Amblyopia has been the subject of much research including a Nobel Prize to Hubel and Weisel for issues related to central nervous function from the eye. The eye and the brain communicate during the first 6 to 8 years of life and learn how to "talk" to each other. Along with this communication other senses tell the brain whether the information from the eye is consistent with, for instance, hand position. If there is a disparity (one image out of alignment or one image unclear) the brain will learn to ignore that image. The eye doctor will examine the situation to determine the cause and if correctable. In the case of cataract or high refractive error, there is a good chance for improvement. The list of possible causes is large including the two common ones of high refractive error and a wiring deficiency which prevents the normal coordination of the eye position. Patching of the good eye to force the brain to improve communication with the bad eye is commonly used.
All this being said, if the eyes pass through the so called "critical" period at age 8, with poor central vision in one eye (almost always there is good peripheral vision), then the situation becomes permanent (probably the first sign of aging of the brain), and nothing after that can be done to improve it. Surgery to align the eyes can be done for appearance reasons but will not affect the vision. Since there is not excellent central vision to keep the eyes in alignment, the eyes can drift over the years (in or out) but re-surgical alignment can be done. There is no scientific evidence in the literature that supports any benefit of vision therapy. Until we learn how to turn back on the nerves in the brain that ignore the image in adulthood, the person with this problem will have to simply adapt to the situation which occupationally is not a bar to employment in all but a very tiny number of jobs. This continues to be an area of active medical research.
Answered by: Richard Bensinger, MD
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