Risk Factors for Age-Related Macular Degeneration
On this page you will find information on:
Risk Factors for Age-Related Macular Degeneration
- Age (3.8 percent of Americans between the ages of 50-59 have either intermediate or advanced age-related macular degeneration; by ages 70-79, this increases to 14.4 percent.)
- Smoking
- Family history of macular degeneration (Those with relatives who have macular degeneration are at greater risk of developing the disease.)
- Gender (Women appear to be at slightly higher risk.)
- Race (Non-Hispanic Caucasians, especially those with fair complexions and light-colored eyes, are at a higher risk than African Americans.)
- Prolonged sun exposure (Visible and ultraviolet light may damage the retina.)
- A high fat diet, and/or one that is low in nutrients and antioxidants.
- Obesity
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Heredity & Age-Related Macular Degeneration
Age-related macular degeneration typically affects individuals over 50 years old. Scientific evidence shows that genes may play a role in the development of nearly three out of four cases of this devastating eye disease.
Several genes are believed to be strongly associated with the risk of developing macular degeneration:
- SERPING1 – A variant of this gene appears to offer protection against macular degeneration. Researchers have determined that proteins are expressed by the SERPING1 gene in the retina and choroid (a layer that contains blood vessels and nourishes the retina). The proteins are involved in regulating the body's immune system, suggesting that the retina and choroid layer are attacked when the immune system malfunctions.
- Factor H and Factor B genes are responsible for proteins that help regulate inflammation in the part of the immune system that attacks diseased and damaged cells. According to study results published in 2006 by Columbia University, 74 percent of age-related macular degeneration patients carry certain variants in one or both of these genes, and these may significantly increase their risk of developing it.
- PLEKHA1 – a gene located on chromosome 10; researchers believe it may increase the risk of developing age-related macular degeneration. Like Factors H and B, PLEKHA1 appears to be involved in the cellular processes related to inflammation.
- LOC387715 – A certain variation of this gene appears to increase the risk of developing age-related macular degeneration. This risk is further heightened if a person with this gene variation also smokes.
- HTRA1 – Scientists have identified a link between a mutation in this gene and the development of macular degeneration. Specifically, the HTRA1 mutation is thought to be associated with the formation of drusen (yellow deposits of waste products under the retina that are often a sign of dry macular degeneration), and may also promote the growth of fragile new blood vessels typical of wet macular degeneration.
- Complement C3 – Researchers have found that a variant in this gene increases the risk of developing the wet and dry forms of macular degeneration. This gene plays an important role in the immune system, leading scientists to believe that inflammation is a vital part of the macular degeneration disease process.
Other gene candidates are being studied to determine their role in macular degeneration. While there is definitely a strong genetic component to this disease, it is highly likely that its development is due to a combination of multiple factors including gene mutations or variations and environmental factors such as sunlight exposure, diet and smoking.
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Protecting Eye Health and Possible Prevention against Macular Degeneration
Healthy Lifestyle, Healthy Eyes
The following suggestions will help protect your vision, improve your overall health, and potentially lower your risk of developing macular degeneration:
- Eat a varied and nutritious diet that includes leafy green vegetables, fruit, fish and foods containing vitamins D, E and C, beta carotene and omega-3 fatty acids. Read below for more information on healthy “vision” foods.
- Exercise regularly.
- Maintain a healthy weight.
- Keep blood pressure at a normal level and control other medical conditions.
- Do not smoke.
- Prevent overexposure to sunlight by wearing sunglasses and hats.
- Regularly visit an eye doctor for comprehensive eye exams.
- Perform Amsler grid tests at home.
“Vision” Foods to Include in Your Diet
- Dark green, yellow and orange fruits and vegetables. These contain carotenoids which may defend against a number of medical conditions, including age-related macular degeneration. Lutein and zeaxanthin are two especially important carotenoids related to vision health. Lutein is found in dark, leafy greens such as spinach, collard greens and kale, as well as in okra, broccoli, papaya, oranges, kiwi, mango, green beans, peaches, sweet potatoes, lima beans, squash, red grapes and green bell pepper. Egg yolks also contain lutein. Yellow corn, honeydew melon, squash, oranges, mango, kale, apricots, peaches and orange bell pepper are good sources of zeaxanthin.
- Fruits and vegetables abundant in vitamin C including green peppers, citrus fruits, tomatoes, broccoli, strawberries, sweet and white potatoes, leafy greens and cantaloupe.
- Eggs, fortified cereals, fruit, wheat germ, green leafy vegetables, nuts, nut oils, vegetable oils and whole grains. These all contain vitamin E.
- Wild salmon, tuna, sardines, walnuts and flaxseed oil. These are good sources of omega-3 fatty acids.
- Whole grain versions of rice, bread and pasta that contain complex carbohydrates which are metabolized more slowly and are healthier than their “white” counterparts. (White rice, bread and pasta have a high glycemic index meaning that the carbohydrates are broken down rapidly into glucose or blood sugar. They provide quick energy but contain few nutrients and little fiber, and in large amounts they may damage cells. Some studies have shown that eating foods with a high glycemic index may increase the risk of developing macular degeneration.
Special Vitamins for Dry Macular Degeneration
The National Eye Institute’s Age-Related Eye Disease Study (AREDS) found that taking a specific high dose formula of antioxidants and zinc (500 milligrams of vitamin C, 400 International Units of vitamin E, 15 milligrams of beta-carotene, 80 milligrams of zinc as zinc oxide, and two milligrams of copper as cupric oxide) may delay or prevent intermediate age-related macular degeneration from progressing to the advanced stage. The antioxidant vitamins and minerals in the AREDS formula help maintain healthy cells and tissues and may prevent damage in the macula. There is no evidence, however, that the AREDS formula provided any benefit to people with early stage age-related macular degeneration. Patients with intermediate age-related macular degeneration in one or both eyes or advanced age-related macular degeneration (dry or wet) in one eye but not the other eye should consider taking the formula. Always consult a physician before taking any supplements. The AREDS formula may be contraindicated due to other medical conditions or other medications.
The NEI has begun AREDS-2 trials focused on the addition of lutein, zeaxanthin and omega-3 fatty acids to the original AREDS formula. Researchers are interested in the effect of these supplements on the progression to advanced age-related macular degeneration and/or moderate vision loss in those at risk of progression. Participants will also be offered variations on levels of beta-carotene and zinc that were included in the original AREDS formula. Scientists will follow up for at least five years.
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Further Information
The following publications from AHAF can provide you with more information:
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Disclaimer: The information provided in this section is a public service of the American Health Assistance Foundation, and should not in any way substitute for the advice of a qualified healthcare professional and is not intended to constitute medical advice. Although we take efforts to keep the medical information on our website updated, we cannot guarantee that the information on our website reflects the most up-to-date research. Please consult your physician for personalized medical advice; all medications and supplements should only be taken under medical supervision. The American Health Assistance Foundation does not endorse any medical product or therapy.
Source: Some of the information in this section of our website was obtained from the National Eye Institute and the National Library of Medicine. The American Health Assistance Foundation is grateful to Jeffrey H. Stern, M.D., Ph.D. at the Regenerative Research Foundation in Rensselaer, New York for reviewing aspects of the above content.
Last Reviewed On: 11/07/08
