NEW YORK, Oct 14 (Reuters Health) -- An experimental eye treatment may substantially reduce vision loss among people with age-related macular degeneration, a common cause of blindness in those over age 65.
Photodynamic therapy -- a combination of drug therapy and laser treatment -- reduced vision loss in 67% of people with an aggressive form of the disease, known as wet macular degeneration. By comparison, just about 40% of participants who received a placebo (inactive) treatment maintained their vision, according to a report in the October issue of the journal Archives of Ophthalmology.
"I generally tell my patients who will benefit from this treatment that about one-third of them will still lose vision, but without it two-thirds will lose vision. Put that way, most want it," comments study author Dr. Neil M. Bressler, professor of ophthalmology at the Johns Hopkins University in Baltimore, Maryland, in a written release.
The leading cause of blindness in older Americans, age-related macular degeneration occurs when the central part of the retina (macula) deteriorates. During wet macular degeneration, abnormal leaky blood vessels and scar tissue grow across the center of the retina (the macula). About 15% of all cases of age-related macular degeneration cases are 'wet.'
During photodynamic therapy, doctors inject patients with a light sensitive medication called verteporfin. The drug is absorbed by substances in the blood called lipoproteins. Next, the doctor shines a red laser light into the eye for a minute and a half. The laser activates the drug, which then helps destroy the diseased tissue and blood vessels, leaving normal blood vessels and tissue intact.
"This is not a cure, nor does it apply to those who already have lost significant vision, but it does appear to be effective in preventing further vision loss for some patients who have recently developed the wet form," Bressler points out.
The new study included more than 600 people with macular degeneration from 22 medical centers in North America and Europe. The therapy is currently being reviewed by the US Food and Drug Administration
In a related editorial, Dr. Stuart L. Fine, of the Scheie Eye Institute, University of Pennsylvania in Philadelphia, called the new therapy "a promising new treatment for age-related macular degeneration, the major cause of severe and irreversible vision loss in the United States and in many developed countries."
