Age-Related Macular Degeneration (AMD)
]]>Macular degeneration]]> is a degenerative disease characterized by the breakdown or damage to the central portion of the retina (the light sensitive layer of the eye) known as the macula. Age-related macular degeneration (AMD) is the most common type of macular disease, affecting approximately 1.7 million older Americans. It is the leading cause of visual impairment for people age 75 and older and one of the predominant cause of new cases of visual impairment among those over age 65.
What Is Age-Related Macular Degeneration and How Do I Know If I Have It?
Nearly everyone experiences changes in their vision as they grow older. For example, you may need more light to see, or it may become harder to tell the difference between colors. You may also have difficulty focusing on things that are close to you or adjusting to glare or darkness.
AMD, on the other hand, is a retinal eye disease that causes progressive loss of central vision, leaving only peripheral, or side, vision intact. AMD affects the macula, the central part of the retina, which is located in the back of the eye and responsible for sharp central vision. There are two types of macular degeneration:
Dry AMD: This affects about 90% of those with the disease. Gradually, the light sensitive cells in the macula break down. Dry AMD may cause symptoms in just one eye at first. In most cases you will get the disease later in the other eye. Symptoms of dry AMD include:
- Words in books, magazines, and newspapers appear blurry
- Dark or empty spaces block the center of your vision
There are currently no established treatment options for dry AMD. However the Age-Related Eye Disease Study (AREDS) showed a reduction in the risk of advanced age-related macular degeneration (AMD) by 25% over seven years by taking a particular vitamin formulation.
Wet AMD: Although only 10% of all people with AMD have this type, it accounts for 90% of all severe vision loss from the disease. It occurs when new blood vessels behind the retina start to grow in the macular region. Onset and progression are rapid. Symptoms of wet AMD include:
- Straight objects in your field of vision, such as telephone poles, the sides of buildings, and streetlight posts appear wavy or otherwise distorted
- Dark or empty spaces block the center of your vision
Treatments for wet AMD include laser photocoagulation, which is a surgical procedure involving a laser to seal and halt or slow the progression of abnormal blood vessels and photodynamic therapy (PDT); or a therapy that uses a nonthermal (cold) laser with an intravenous light-sensitive drug to destroy the abnormal blood vessels.
More recently Anti-VEGF treatment has become the mainstay of therapy. It is the first and only treatment clinically proven to restore vision in patients with wet AMD. The anti-VEGF drugs work by inhibiting the growth of new blood vessels.
If you notice changes in your vision, you should contact your eye doctor immediately. The earlier AMD is diagnosed, the better the chances of preventing vision loss.
Reducing Your Risk of Age-Related Macular Degeneration
Although scientists don’t yet know what causes AMD or how to fully prevent it, there are steps you can take to lower your chances of developing AMD and delay its progression:
- Make regular exams a priority. Early detection of AMD through regular eye exams is critical. The American Academy of Ophthalmology recommends that individuals age 40–64 with no AMD symptoms have eye exams every 2-4 years; after age 65, eye exams should occur every 1-2 years (or more frequently if recommended by your eye care specialist). Remember that people with certain eye and medical conditions require eye examinations much more frequently.
Control your risk factors. Quit smoking. Manage
]]>high blood cholesterol]]>
]]>blood pressure]]>. Eat a healthful diet low in saturated fat and rich in fruits and green, leafy vegetables. These contain lutein, which has shown promise in one small clinical trial for fighting macular degeneration and zeaxanthin which is hypothesized to be protective.
Also, the results of one large clinical trial, called the Age-Related Eye Disease Study, indicated that somewhat high dosages of zinc, with or without the antioxidant vitamins ]]>C]]> and ]]>E]]>, and ]]>beta-carotene]]>, might help to significantly reduce the risk of developing advanced stages of AMD for people who already have moderate AMD. But, researchers could not determine whether the effect would last over a long period of time or with different doses of these or other supplements. You can also protect your eyes from damage by UV light by wearing brimmed hats and UV-protected sunglasses.
What Are My Options If I Have AMD?
If you have AMD, you can continue to lead an active and independent life. Even if you have experienced some vision loss, normal use of your eyes (watching TV, reading, etc.) will not cause further damage to your vision.
Low-vision aids (special lenses or electronic systems that make images appear larger) are available to help you make the most of your remaining vision. Your eye care professional can prescribe them or refer you to a low-vision specialist. In addition, groups and agencies that offer information about counseling, training, and other special services are available. You may also want to contact a nearby school of medicine or optometry as well as a local agency devoted to helping the visually impaired.
Lastly, by staying well-informed, you can learn what problems may develop with your vision, how those problems can be detected, and what steps you can take to save your remaining sight.
AMD Alliance International
American Academy of Ophthalmology
National Eye Institute
Prevent Blindness America
BC Health Guide
Canadian Ophthalmological Society
AMD information. AMD Alliance International website. Available at: http://www.amdalliance.org/AMD_Information. Accessed May 15, 2008.
American Macular Degernation Foundation Website. Available at: http://macular.org/.
Facts about age-related macular degeneration. National Eye Institute, National Institutes of Health (NIH) website. Available at: http://www.nei.nih.gov/health/maculardegen. Accessed May 15, 2008.
Frequently asked questions about age-related macular degeneration. Prevent Blindness America website. Available at: http://www.preventblindness.org/eye_problems/amdFAQ.html. Accessed May 15, 2008.
General practitioners’ information about AMD. AMD Alliance International website. Available at: http://www.amdalliance.org/Press_Room. Accessed May 15, 2008.
Growing older with good vision. Prevent Blindness America website. Available at: http://www.preventblindness.org/eye_problems. Accessed May 15, 2008.
Macular Degeneration Partnership Website. Available at: http://www.amd.org/site/PageServer?pagename=anti_angiogenesis.
Results: age-related eye disease study. National Eye Institute, National Institutes of Health (NIH) website. Available at: http://www.nei.nih.gov/amd/. Accessed May 15, 2008.
Richer S, Stiles W, Statkute L, et al. Double-masked, placebo-controlled, randomized trial of lutein and antioxidant supplementation in the intervention of atrophic age-related macular degeneration: the Veterans LAST study (Lutein Antioxidant Supplementation Trial). Optometry. 2004;75:216-30.
Take care of your family’s eyes. American Academy of Ophthalmology website. Available at: http://www.aao.org/aao/news/release. Accessed September 9, 2003.
Last reviewed April 2008 by ]]>Eric L. Berman, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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