News Releases

Oct. 12, 2001

Emory Eye Center Reports Important Findings from National AREDS Study: Macular Degeneration Progression Can Be Slowed for Those at High Risk

EMORY Health Sciences News
Robert W. Woodruff Health Sciences Center
Health Sciences Communications

(ATLANTA) Findings were released today detailing the results of an important 10-year study which had a two-fold purpose:

• To assess the clinical course, prognosis, and risk factors of age-related macular degeneration (AMD) and cataract.
• To evaluate, in randomized clinical trials, the effects of pharmacologic doses of antioxidants and zinc on the progression of AMD and (2) antioxidants on the development and progression of lens opacities (cataract).

Titled the Age- Related Eye Disease Study (AREDS), the clinical trial was conducted at 11 centers across the country, including the Emory Eye Center. The results show that there is a relatively simple way to help prevent the progression of age-related macular degeneration (AMD) in patients at high risk of the disease. “This is a particularly important finding since prior to this study, there was no way to slow the progression of AMD,” says Principal Investigator Daniel F. Martin, M.D., a vitreoretinal specialist at the Emory Eye Center. The AREDS was sponsored by the National Eye Institute (NEI), one of the federal government's National Institutes of Health. The study’s findings are reported in the October issue of Archives of Ophthalmology.

AMD is the leading cause of visual impairment and blindness in Americans over 65 years of age. It affects the sharp, central vision required for “straight ahead” activities such as reading, driving, and recognizing faces. The AREDS results show that a dietary supplement of high levels of antioxidants and zinc significantly reduced the risk of advanced AMD and its associated vision loss in patients at high risk of developing advanced stages of AMD.
These same supplements had no significant effect on the development or progression of cataract, the study found. Although the current study indicated that the dietary supplements did not affect the development of cataract, an effect over a longer period of time—or with different doses of these antioxidants—cannot be ruled out. The three stages of AMD analyzed in the study included:

• Early AMD: Patients with early AMD have, in one or both eyes, either several small drusen (yellow deposits under the retina) or a few medium-sized drusen; these patients do not have vision loss from AMD.

• Intermediate AMD: Patients with intermediate AMD have, in one or both eyes, either many medium-sized drusen or one or more large drusen; in these people, there is usually little or no vision loss.

• Advanced AMD: In addition to drusen, patients with advanced AMD have, in one or both eyes, either: a breakdown of light-sensitive cells and supporting tissue in the central retinal area (advanced dry form); or (2) abnormal and fragile blood vessels under the retina that can leak fluid or bleed (wet form).

These two forms (wet or dry) of advanced AMD can cause serious vision loss. Scientists are unsure why an increase in the size and number of drusen can lead to advanced AMD, but patients who have advanced AMD in one eye are at especially high risk for developing it in the other eye. The AREDS scientists found that their patients at high risk of developing advanced stages of AMD lowered this risk by approximately 25 percent when treated with a high-dose combination of Vitamin C, vitamin E, beta-carotene and zinc. “High risk” is defined as: 1) intermediate AMD in one or both eyes; and 2) advanced AMD in one eye, but not the other eye.

In the same high-risk group—which includes people with intermediate AMD, or advanced AMD in one eye but not the other eye—these supplements (antioxidants plus zinc, as above) reduced the risk of vision loss caused by advanced AMD by about 19 percent. For those study participants who had either no AMD or early AMD, the supplements did not provide an apparent benefit.

What This Result Means
For people at high risk for developing advanced AMD, these supplements are the first effective treatment to slow the progression of the disease. Current treatment for advanced AMD is quite limited. These dietary supplements will delay the progression to advanced AMD in those people who are at high risk (those with intermediate AMD in one or both eyes, or those with advanced AMD in one eye already). The supplements are not a cure for AMD, nor will they restore vision already lost from the disease. They will, however, help those at high risk from developing an advanced stage of the disease and help them keep their vision.
What Are the Supplements?
The supplements used in the study which slowed the progression to advanced AMD consisted of several antioxidant vitamins. They also contained zinc. The supplements 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 (to help prevent copper deficiency, which may result from high levels of zinc supplementation). Although previous studies have shown that diets rich in green, leafy vegetables lower the risk of developing AMD, diet alone cannot approximate the levels of the supplement used in this study.
Participants in this study were divided into four treatment groups that received: 1) zinc alone; 2) antioxidants alone; 3) a combination of antioxidants and zinc; or 4) a placebo, a harmless substance that has no medical effect. The benefits were seen only in people who began the study at high risk of developing advanced AMD—those with intermediate AMD, and those with advanced AMD in one eye only. In this group, those taking “antioxidants plus zinc” had the lowest risk of developing advanced stages of AMD and its accompanying vision loss. Those in the “zinc alone” group or “antioxidant alone” group also reduced their risk of developing advanced AMD, but at more moderate rates compared to the “antioxidant plus zinc” group. Those in the placebo group had the highest risk of developing advanced AMD.

There were 4,757 patients studied nationwide; 438 patients were studied at the Emory Eye Center. The average length of study for each patient at Emory was 6.5 years. Emory patients came from several Southeastern states, including Florida, Georgia, Louisiana, South Carolina, North Carolina, Tennessee and Texas. Patients at Emory were ages 60 to 80 and were equally represented by gender.

“At Emory we are also looking at other compounds that may have a promising effect in delaying the onset of macular degeneration,” says Paul Sternberg, Jr., M.D., director of the Vitreoretinal Surgery & Diseases section at the Emory Eye Center. “AREDS is the first important step in developing a therapeutic approach to dry macular degeneration. In our labs we are studying several promising agents that may be even more effective. Down the road, we look forward to future clinical trials that may provide new answers to this disease.”

Emory Eye Center Director Thomas M. Aaberg, Sr., M.D. says, “We are very pleased to have been involved in this important study. The Emory Eye Center’s pre-eminence in the field of ophthalmology is again demonstrated with its inclusion in this important trial. We are the only AREDS clinical trial center in the Southeast, and as such, we are pleased to help in the fight to prevent blinding eye disease.”

“These findings are only a part of what we will learn from AREDS about macular degeneration. We will continue to answer many more questions in the next five years as we continue to follow these patients,” says Dr. Martin.

Media Contact: Joy H. Bell
jbell@emory.edu
404-778-3711

Our Emory campus location:

Copyright © Emory Eye Center - All Rights Reserved | Emory Clinic Building B, 1365B Clifton Road, NE, Atlanta, Georgia 30322 USA