If every American at risk for advanced age-related
macular degeneration took daily supplements of antioxidant
vitamins and zinc, more than 300,000 people could avoid
AMD-associated vision loss over the next five years,
according to results of a new government study led in part
by researchers at Johns Hopkins'
Wilmer Eye
Institute.
Reporting on the public health implications of the
national Age-Related Eye Disease Study, published two years
ago and supported by the National Eye Institute, a team of
Johns Hopkins ophthalmologists and other scientists
participating in AREDS estimate there are 8 million people
in the United States age 55 or older at high risk for
advanced forms of the disorder that destroys central vision
and who could benefit from daily vitamin treatment. They
include people with an intermediate stage of AMD in one or
both eyes, or advanced AMD in one eye. AMD is the leading
cause of blindness in developed countries.
The original AREDS investigation, of 4,757 adults ages
55 to 80 with varying levels of AMD, showed that among
people at high risk for late-stage AMD and central vision
blindness in both eyes, a dietary supplement of vitamins C,
E and beta carotene along with zinc lowered the risk of
progressing to advanced disease by about 25 percent. Daily
supplements also reduced the risk of vision loss by about
19 percent. By contrast, the supplements had no preventive
effects against development of cataracts or for people
without AMD or an early stage of AMD.
"Without treatment to reduce their risk, we estimate
that 1.3 million adults would develop the advanced stage of
AMD," said Neil M. Bressler, lead author of the current
study, published in the November issue of the Archives of
Ophthalmology, and the James P. Gills Professor of
Ophthalmology at Johns Hopkins. "The challenge lies in
identifying individuals at risk, since many with the
intermediate stage of AMD do not have symptoms. Regular
retina exams performed by an ophthalmologist could identify
those in this intermediate stage."
Bressler and colleagues estimate that, without
treatment, the prevalence of advanced AMD within five years
among those with intermediate AMD in one eye is 6.3
percent. They also estimate 26.4 percent of those with
intermediate AMD in both eyes and 43 percent of those with
advanced AMD in one eye would develop advanced AMD in five
years without treatment.
The supplements recommended contain 500 milligrams of
vitamin C, 400 milligrams of vitamin E, 15 milligrams of
beta carotene, 80 milligrams of zinc as zinc oxide and 2
milligrams of copper as cupric oxide.
Co-authors of the current report with the AREDS
Research Group, supported by the National Institutes of
Health and Bausch & Lomb, were Susan B. Bressler, Nathan G.
Congdon, Frederick L. Ferris III, David S. Friedman, Ronald
Klein, Anne S. Lindblad, Roy C. Milton and Johanna M.
Seddon.
Related Web Sites
Wilmer Eye Institute at Johns Hopkins
National Eye Institute — AREDS study
Archives of Ophthalmology
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