An eye operation that moves the most light-sensitive part of the retina away from an underlying diseased area has saved sight in several people with a common, age-related eye disease.
The operation promises to save the vision of thousands of people threatened by age-related macular degeneration (AMD), the major cause of blindness in people over 55 years.
The technique, called macular translocation, is used in cases of AMD in which abnormal blood vessels grow and bleed underneath the retina, according to Eugene de Juan, M.D., professor of ophthalmology at the Wilmer Eye Institute. The growth of abnormal blood vessels occurs in choroid, the layer of blood vessels under the retina, causing the bleeding, or "wet" form of AMD.
"It's almost unheard of for someone with new blood vessels under the central retina caused by AMD to regain normal vision," says de Juan. "In contrast to the natural course of the disease, the vision in the eye of one of my patients improved after surgery from 20/160 to 20/30." A person with 20/160 vision sees clearly an object at 20 feet that a person with normal vision can see clearly at 160 feet. A vision of 20/20 is considered normal.
De Juan, who perfected the technique after modifying earlier, less successful surgical strategies, reports the results of the surgery in the first three patients in the May issue of the American Journal of Ophthalmology. He has now performed the same procedure on a total of 40, about 20 percent of whom have had their vision restored enough to read and drive.
"This technique gives us an important additional therapy used in conjunction with lasers," de Juan says. "The problem with treating the wet form of AMD with the laser is that you also destroy the functioning macula. That's like cutting off a leg to save your life. You end up alive but disabled."
In the new procedure, de Juan pinches the sclera, the white, outer part
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Contact: Marc Kusinitz
mkusinit@welchlink.welch.jhu.edu
(410)955-8665
Johns Hopkins Medical Institutions
20-May-1998