Age-related macular degeneration (AMD) is a leading cause of severe, irreversible vision impairment in the United States. It affects the macula, the central part of the retina supplying central vision.
There are two types of AMD: dry and wet. Dry AMD, also known as atrophic or non-exudative AMD, is the most common form, accounting for at least 80 percent of patients with AMD. It tends to progress slowly over many years to affect central vision. Despite the smaller population of patients with wet AMD, also known as neovascular or exudative AMD, this group accounts for 90 percent of severe vision loss from AMD.
The National Eye Institute sponsored a clinical trial called the Age-Related Eye Disease Study (AREDS), which evaluated the use of a high-dose combination of vitamin C, vitamin E, beta-carotene and zinc for patients with varying degrees of macular degeneration.
The study found that people at high risk of developing advanced stages of AMD lowered their risk by about 25 percent, recommending patients with intermediate AMD or advanced AMD in at least one eye take AREDS supplements with this formulation of antioxidants and zinc to decrease the risk of vision loss from AMD.
Another study, the Age-Related Eye Disease Study 2 (AREDS2), was created to evaluate whether adding different antioxidants (lutein and zeaxanthin) along with omega 3 fatty acids to the AREDS formulation could decrease the risk of developing advanced AMD. It also evaluated the effect of eliminating beta-carotene and lowering the dose of zinc. The study showed no additional benefit in lowering the risk of advanced AMD by adding these new items to the original AREDS formulation. However, participants who took AREDS supplements containing the newer antioxidants with no beta-carotene had a slight reduction in the risk of advanced AMD compared to those who took supplements with beta-carotene.
This is important since beta-carotene can increase the risk of lung cancer in smokers. Also, for a subgroup of participants with very low levels of antioxidants in their diet, adding these new antioxidants to the AREDS formulation helped lower their risk of advanced AMD and even decreased progression to cataract surgery. These findings allowed for the creation of an improved AREDS2 formulation.
Those with AMD should schedule annual eye exams, avoid smoking or secondhand smoke, eat a diet rich in green, leafy vegetables and natural omega 3 fatty acids, wear sunglasses with 100 percent UV protection and exercise regularly. Those with intermediate or advanced AMD are recommended to take AREDS2 formula eye vitamins.
Each eye should be checked daily with an Amsler grid, a square box with vertical and horizontal lines surrounding a central point of fixation. Straight lines that become wavy may be a sign of wet AMD, and an eye doctor should be contacted immediately. Early intervention has revolutionized outcomes for patients with wet AMD by decreasing progression and sometimes even improving vision. While genetic testing is available for genes associated with AMD, its routine use is not supported by the current literature and not recommended at this time.
If you have concerns about your vision, it is important to speak to a doctor to discuss treatment options. Dr. E. Trevor Elmquist, Dr. Kate Wagner, Dr. Nina Burt, and Dr. Sarah Eccles-Brown of Elmquist Eye Group
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