Macular degeneration affects around 10 percent of Americans between the ages of 66 to 74, the University of Illinois Eye and Ear Infirmary reports. The leading cause of vision loss in people over 65, according to the website All About Vision, macular degeneration progresses from the early dry form to a more vision-threatening wet form in around 15 percent of people with the disease. There’s no treatment for dry macular degeneration in 2010, but completed clinical trials show that in some patients vitamin supplements may prevent progression to wet age-related macular degeneration, or AMD. Clinical trials to evaluate other formulations are ongoing.
AREDS Formula
AREDS stands for Age-Related Eye Diseases Study. Conducted by the National Eye Institute, the AREDS study followed around 3,600 people taking a certain combination of vitamins over a six-year period. The AREDS formulation combines 500mg of vitamin C, 400 international units of vitamin E, 15mg of beta-carotene, 80mg of zinc oxide and 2mg of copper, the National Eye Institute reports. The formulation reduced the risk of progression from advanced dry AMD to wet by around 25 percent. Smokers may have an increased risk of lung cancer if they take extra beta-carotene, so a formulation without beta-carotene is available for smokers and ex-smokers.
Lutein and Zeaxanthin
Lutein and zeaxanthin, antioxidants found in egg yolks, corn, spinach and other leafy green vegetables in high amounts, reduced the risk of developing wet AMD in people with the dry form in at least one study, the University of Maryland Medical Center reports. Lutein and zeaxanthin absorb blue light, the light most damaging to the eye, according to the University of Illinois Eye and Ear Infirmary. The AREDS II study, which has around 4,000 people enrolled and will end around 2012, is testing a combination of lutein and zeaxanthin and omega-3 long-chain polyunsaturated fatty acids.
Omega-3 Fatty Acids
Two omega-3 long-chain fatty acids, ocosahexaenoic acid and eicosapentaenoic acid, are currently under clinical trial in the AREDS II study for use in reducing wet AMD. The University of Maryland reports that several studies have found some benefit in adding dietary omega-3 fatty acids several times a week to reduce the risk of developing AMD. The original AREDS study found that people with the highest intake of omega-3 poly-unsaturated fatty acids were 50 percent less likely to develop wet AMD, reports ophthalmologist James Polk, M.D, of the University of Iowa.
