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FDA Supporting Blindness Treatment
© The Associated Press
By RANDOLPH E. SCHMID
WASHINGTON (AP) - Advisers to the Food and Drug Administration on Wednesday indicated support for a light-activated drug to battle a form of creeping blindness that afflicts the elderly, but they stopped short of giving it a formal endorsement.
``The committee looked favorably upon the benefits over the risks'' of Visudyne, said Dr. Donald S. Fong of Kaiser Permanente Medical Center in Baldwin Park, Calif., chairman of the Food and Drug Administration's ophthalmic drugs advisory subcommittee.
His comments followed a daylong session discussing the drug, used in light therapy for macular degeneration, the major cause of blindness in the elderly. Visudyne is made by QLT Therapeutics of Vancouver, British Columbia, Canada.
The panel did not take a formal vote on whether to recommend approval of the drug, which the FDA is considering. Several committee members indicated they wanted to see the results of a second year of clinical trials. Fong noted that some patients required more than one treatment in the initial trials.
Even if the panel had voted, the FDA is not bound by advisory committee recommendations. However, it does give them serious weight in making decisions on what drugs to approve.
Age-related macular degeneration, or AMD, tends to affect people over 50. There are 1.7 million people already legally blind and there is a potential for far more as the elderly population grows in coming years.
The first symptom is that fine detail fades. Readers can't focus on just one word and people's faces start to blur. Eventually people lose the ability to read or drive and eventually, in the worst cases, blindness follows.
Visudyne can't restore already-lost vision, but may be able to slow down vision loss, researchers said.
Fong noted that the drug delayed the deterioration of vision in patients by six months or so, a seemingly modest benefit but one that can be very important to the elderly.
There are two types of AMD that affect the macula, the light-sensitive layer of tissue in the center of the retina.
Visudyne is designed to treat the less common but much worse form of the disease, called ``wet'' AMD, that occurs when new blood vessels form behind the retina, leaking into the macula and rapidly destroying it. It often progresses to blindness within two years.
The wet form of the disease represents an estimated 15 percent of all AMD cases, but accounts for approximately 90 percent of the severe vision loss associated with the disease.
There is one treatment, a laser that cauterizes the blood vessels. But only about 15 percent of patients qualify because, if the blood vessels are in the wrong spot, the laser can do more harm than good.
Visudyne is light-activated. The drug is injected into the arm and then migrates into the eye's abnormal blood vessels. Shine in a non-burning beam of light and the drug is activated, preventing the growth of those blood vessels without hurting surrounding tissue.
Patients undergoing treatment are advised to avoid direct sunlight for several days.
The second form of AMD - ``dry'' AMD - accounts for the majority of cases. It slowly breaks down the macula's light-sensitive cells. There is currently no treatment, but the damage occurs very slowly so victims only gradually notice a blind spot in their central vision and don't completely lose their sight.
Copyright 1999 The Associated Press. The information contained in the AP news report may not be published, broadcast, rewritten or otherwise distributed without prior written authority of The Associated Press.
Date last modified November 21, 1999