When a child is farsighted or has astigmatism or has both conditions in both eyes, bilateral amblyopia may develop. In contrast to single-eye amblyopia or “lazy eye,” where one eye presents an unclear image to the brain, bilateral amblyopia affects both eyes and is less common.
In an article published in the October issue of the American Journal of Ophthalmology, researchers report that this condition can be successfully treated with corrective lenses, particularly when diagnosed and treated early. Left untreated, bilateral amblyopia may result in permanent visual disability.
The Pediatric Eye Disease Investigator Group (PEDIG) conducted a study of 113 children between 3 and 9 years-old with bilateral refractive amblyopia, who were treated with glasses and followed prospectively at 27 community- and university-based sites. After one year, visual acuity measured with both eyes open had improved an average of about 4 lines on the traditional Snellen eye chart. Average visual acuity improved from 20/63 to 20/25, and most children (74%) reached 20/25 or better. Those children who started with visual acuity of 20/100 or worse showed the greatest improvement, averaging 6.3 lines after one year.
“This study shows that glasses are a powerful treatment for bilateral amblyopia in children. When we detect and treat this problem early in life, most children are able to achieve normal vision,” said Paul A. Sieving, M.D., Ph.D., Director of the National Eye Institute, one of the Federal government’s National Institutes of Health and the agency that sponsored the study.
“Most ophthalmologists or optometrists will see no more than a few cases of bilateral amblyopia each year, which is not enough to be able to do a large study on this condition. The structure of the Pediatric Eye Disease Investigator Group allows us to enroll children at multiple sites to do large studies of important but relatively uncommon conditions like bilateral amblyopia,” said David Wallace, M.D., lead author for the study.