ROCKVILLE, MARYLAND. Age-related macular degeneration (AMD) is the leading cause of blindness amongst people 65 years or older. The macula is the central portion of the retina (back surface of the eyeball) directly opposite the lens. In macular degeneration the light-sensing cells of the macula malfunction and may eventually cease to work at all. The presence of drusen (waste deposits on the underside of the retina) is a precursor of AMD and can be observed during an eye examination.
Researchers at the National Eye Institute now report that supplementation with zinc and antioxidants can markedly retard the progression from the presence of extensive drusen to full-blown AMD. The study involved 3640 participants between the ages of 55 to 80 years. They had a thorough eye examination that divided them into four groups. Group 1 had few if any drusen, group 2 had extensive small drusen, group 3 had extensive intermediate-size drusen or at least one large drusen, and group 4 had advanced AMD or visual acuity less than 20/32 due to AMD in one eye. The participants were then randomized to receive daily oral supplements as follows:
The progression towards AMD was measured at six-month intervals for an average of 6.3 years. At the end of the trial the researchers observed that daily supplementation with antioxidants and zinc (A + B) reduced the risk of progression to advanced AMD by 25 per cent in groups 3 and 4. The incidence of progression to advanced AMD in groups 1 and 2 was so low, even with placebo treatment, that no benefit of supplementation was observed.
The researchers conclude that patients with extensive drusen or advanced AMD should consider taking zinc
and antioxidants in the dosages used in the study. They found no indication of serious adverse effects from
the treatment, but warn that smokers may wish to avoid beta-carotene.