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March 1 2003 • Volume 36 • Number 5
Age-related macular degeneration
Dietary Supplements Can Reduce Risk of Vision Loss
Kerri Wachter
Senior Writer
BETHESDA, MD. — Dietary supplements containing high levels of antioxidants and
zinc significantly reduced the risk of vision loss among patients with
intermediate age-related macular degeneration, Dr. Emily Chew said at a
conference sponsored by the National Institutes of Health Office of Dietary
Supplements.
The beneficial effect also was seen in patients with advanced age-related
macular degeneration (AMD) in one eye, said Dr. Chew of the National Eye
Institute, Bethesda.
Elderly patients at high risk of developing advanced stages of AMD reduced the
risk of vision loss by 19% when treated with a high-dose combination of vitamin
C, vitamin E, beta carotene, and zinc. Patients in the same high-risk group who
were on the high-dose regimen also had a nearly 25% risk reduction in the
development of advanced stages of AMD.
No benefit was shown for patients without AMD or with early AMD.
The Age-Related Eye Disease Study—which involved 4,757 patients aged 55-80
years—randomized patients to receive zinc alone, antioxidants alone, a
combination of antioxidants and zinc, or placebo. The antioxidant/zinc
formulation contained 500 mg of vitamin C, 400 IU of vitamin E, 15 mg of beta
carotene, 80 mg of zinc (as zinc oxide), and 2 mg of copper (as cupric oxide)
and was taken daily in tablet form (Arch. Ophthalmol. 119[10]:1417-36, 2001).
Benefits were seen only in those patients who had intermediate AMD or advanced
AMD in one eye. Patients in this group who took the antioxidants and zinc had
the lowest risk of developing advanced AMD and vision loss. Patients who had
intermediate AMD or advanced AMD in one eye who took either antioxidants or zinc
also reduced their risk of developing advanced AMD and vision loss, but did so
at more moderate rates than those in the zinc plus antioxidants group.
The presence of drusen—yellow deposits under the retina—is a marker for macular
degeneration. Drusen do not cause vision loss, but an increase in their size or
number increases the risk of developing advanced AMD. Drusen can be detected
during an eye exam in which the pupils are dilated, Dr. Chew noted at the
conference, which was also sponsored by the National Institute on Aging.
An ophthalmologist can easily identify the presence, size, and quantity of
drusen deposits to determine a patient's risk for AMD and can consult with
primary care physicians about whether to recommend this supplement combination.
The study also evaluated the effect of high levels of antioxidants and zinc on
the development or progression of cataracts. “Essentially we found no effect of
this supplementation on cataracts or visual acuity,” she said.
An increase in the size or
number of drusen—yellow deposits under the retina—can signal advancing
age-related macular degeneration. Courtesy Dr. Emily Chew
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