Pharmaceutical Corner
Nutrition and the eye

Study shows antioxidant benefit in AMD but none for cataract at this time.

Recent data from the National Eye Institute/National Institutes of Health Age-Related Eye Disease Study (AREDS) concluded that high levels of antioxidants and zinc significantly reduce the risk of advanced age-related macular degeneration by about 25%. These same nutrients also reduce the risk of vision loss caused by advanced AMD by about 19%. However, they have no significant effect on the development or progression of cataract.

According to Frederick Ferris, MD, director of clinical research at the NEI and AREDS chairman, patients older than 55 years with extensive intermediate drusen, at least one large drusen, noncentral geographic atrophy in one or both eyes, or advanced AMD or vision loss due to AMD in one eye, should consider taking antioxidant supplement plus zinc.
Both Ferris and Emily Y. Chew, MD, NIH investigators, presented AREDS data at the recent American Academy of Ophthalmology meeting. The results also were published in the October 2001 issue of Archives in Ophthalmology.

Groundbreaking study

The study looked at the role of vitamins in macular degeneration. УAREDS is a major research program to improve our understanding of the predisposing factors, clinical course, and prognostic factors of AMD and cataract,Ф Ferris said.
For the study, 4,757 patients were randomized to treatment with placebo, antioxidants, zinc, or antioxidants plus zinc, and were followed for a minimum of 5 years. All patients except minority participants were recruited from September 1990 to July 1995. Recruitment of minority patients was completed in August 1997.
Men and women between 55 and 80 whose macular status ranged from no evidence of AMD in either eye to relatively severe disease with vision loss in one eye but 20/30 or better vision in the fellow eye were included in the study. Patients had to have ocular media clear enough to allow for good fundus photography.
The nutrients used in the AREDS study contained 500 mg of vitamin C; 400 international units of vitamin E; 15 mg of beta-carotene; 80 mg of zinc as zinc oxide; and 2 mg of copper as cupric oxide (copper was added to the AREDS formulations containing zinc to prevent copper deficiency, which may be associated with high levels of zinc supplementation).

Results

AREDS researchers found that people at high risk of developing advanced AMD lowered their risk by about 25% when treated with a high-dose combination of vitamin C, vitamin E, beta-carotene, and zinc, Ferris reported.
In the same high-risk group, which includes people with intermediate AMD or advanced AMD in one eye but not the other eye, the nutrients reduced the risk of vision loss caused by advanced AMD by about 19%.
УPrevious studies have suggested that people who have diets rich in green, leafy vegetables have a lower risk of developing AMD,Ф he said. УHowever, the high levels of nutrients that were evaluated in the AREDS are very difficult to achieve from diet alone. Almost two-thirds of AREDS participants chose to take a daily multivitamin in addition to their assigned study treatment.Ф
AREDS also showed that, even with a daily multivitamin, people at high risk for developing advanced AMD can lower the risk of vision loss by adding a formulation with the same high levels of antioxidants and zinc used in the study, he added.
For those study participants who had no AMD or early AMD, the supplements did not provide an apparent benefit. In addition, the investigators found in the cataract portion of the study that the same nutrients had no significant effect on the development or progression of age-related cataract.
Despite the evidence that these nutrients did not lower the risk of cataract development during the 7 years of the study, Ferris said, an effect over a longer period of time or with different doses of these or other antioxidants cannot be ruled out.

Side effects

The AREDS participants reported few side effects from the treatments. About 7.5% of participants assigned to the zinc treatments, compared with 5% who did not have zinc in their assigned treatment, had urinary tract problems that required hospitalization. Participants in the two groups that took zinc also reported anemia at a slightly higher rate. However, testing of all patients for this disorder showed no difference among treatment groups. Yellowing of the skin, a side effect of large doses of beta-carotene, was reported slightly more often by participants taking antioxidants.
In two large clinical trials sponsored by the National Cancer Institute, beta-carotene was shown to significantly increase the risk of lung cancer among smokers.
For more in-depth information about the study go to: www.nei.nih.gov

Eyecare supplements

There is no shortage of available eyecare dietary supplements on the market today. Many vitamin manufacturers have a special Уeye formulaФ and some companies make vitamins with so-called Уvision-relatedФ benefits. The vitamins are available through a variety of venues, including pharmacies and other retailers, physicians, marketing networks, and the Internet (chart). Some selected companies are highlighted.
Bausch & Lomb, of Rochester, N.Y., is a leader in the nutritional eyecare field. Its Ocuvite formulation supplies 100% of the U.S. Daily Values for vitamins C, E, and A. Zinc (as zinc-oxide), copper, and selenium are also included in Ocuvite as essential minerals. The vitamins are sugar and lactose-free.
Ocuvite Extra has the benefits of Ocuvite and includes higher levels of antioxidants and vitamins A, C, and E as well as riboflavin (B-2) and niacinamide (B-3), zinc, selenium, copper, manganese, and L-glutathione. It also contains select B-vitamins (riboflavin and niacinamide).
Bausch & Lomb also manufactures Ocuvite Lutein, an antioxidant supplement that contains essential antioxidant vitamins, minerals, and 6 mg of lutein, a carotenoid, in a single capsule. Ocuvite Lutein also provides 100% of the U.S. daily values for the antioxidant vitamins C, E, and the minerals zinc and copper.
La Haye Laboratories Inc. manufactures and markets astaZANTHIN brand astaxanthin, a branded raw material. AstaZANTHIN is a novel high-potency antioxidant from a natural and highly concentrated source.
LaHaye, of Redmond, Wash., created the ICAPs brand of eyecare vitamins, which was sold to Alcon Laboratories, of Fort Worth, Texas. ICAPs contains antioxidant vitamins and minerals and is available in ICAPs High Potency and ICAPs Time Release. ICAPs, which are sugar- and lactose-free, are available at pharmacies.
ScienceBased Health, of Corte Madera, Calif., recently reformulated its MaculaRx Plus nutritional supplement. MaculaRx Plus contains a blend of antioxidants (vitamin C, E, and beta carotene), zinc, copper, selenium, and 15 mg of lutein, and is designed to preserve macular health, the company says.

ScienceBased Health also manufactures HydroEye (for dry eyes), OculaRx (for Уeyes and overall body healthФ). The formulations are sold through a network of recommending ophthalmologists and optometrists.