Vitamins and Macular Degeneration: What You Need to KnowCreated October 22, 2015 by Kien Phung in Retina Specialist
A quick glance at the vitamins section of your local pharmacy will reveal a myriad of ocular vitamins with various claims ranging from preserving one’s vision to improving one’s eyesight. Most of these vitamins are taken for “macular degeneration.” With so many choices, how does one go about deciding which vitamins are appropriate to take? Are these vitamins even recommended in the first place?
Currently, the leading cause of blindness in people over the age of 65 is age-related macular degeneration (AMD). As baby boomers continue to age, the government projects that by the year 2020, as many as 3 million Americans will be affected by this potentially sight-threatening ocular condition.
There are two basic forms of AMD, dry and wet, with the latter accounting for a majority of cases of legal blindness. Both forms of this condition cause damage to the macula, which is the area of the eye that is responsible for central vision. Hence, in the very worst case scenario, patients lose their central vision, but peripheral vision is still preserved. In the past, there were no satisfying treatments for the wet form of AMD. Fortunately, the relatively recent advent of potent intraocular medications has provided ophthalmologists with a powerful armamentarium to manage wet AMD which was not available over a decade ago. But what of the dry form of AMD that accounts for 85% to 90% of all AMD cases?
As with any other medical conditions, there is a severity scale used to grade dry AMD. In short, dry AMD ranges from mild, intermediate, advanced, to end-staged atrophy. To date, there are no effective treatment for dry AMD. However, the National Eye Institute sponsored a large multi-centered clinical trial — Age-Related Eye Disease Study (AREDS) — evaluating the effectiveness of certain vitamins on reducing the risk of progression of dry AMD. Based on this landmark study, patients with moderate to severe forms of dry AMD benefit from taking high doses of a combination of vitamin C (500mg), vitamin E (400IU), beta-carotene (15mg), zinc (80mg), and copper (2mg). On the other hand, those with mild dry AMD do not appear to reap any benefits from taking AREDS vitamins. Also, there appears to be an association between smokers taking beta-carotene and the higher risk of developing lung cancer.
Consequently, the National Eye Institute launched a subsequent study, AREDS 2, looking at alternative supplements, specifically omega-3-fatty acids, lutein, and zeaxanthin. These potent antioxidants purportedly have beneficial effect on macula wellbeing. Results of AREDS 2 study were released in 2013. Lutein (10mg) and zeaxanthin (2mg) essentially replaced beta-carotene on the new AREDS 2 formula. Overall, the new formula did not show added benefits compared to the original formula as far as preventing the risk of advanced AMD. However, participants who had low dietary intake of lutein and zeaxanthin benefited the most from this new formula. More importantly, AREDS 2 formula appears to be a safe alternative for current and former smokers.
Like all other medications and supplements, taking these high dose AREDS vitamins is not without risks since they may interfere with other medications. This is an important conversation that should be discussed with your ophthalmologist and/or primary care provider.