Age-related macular degeneration (AMD) is the top cause of vision loss in older adults, but you can take certain steps to protect your eyes and preserve your vision.
“AMD is a multifactorial disease related to advancing age, genetics, and environmental exposures,” says Szilárd Kiss, MD, associate professor of ophthalmology at Weill Cornell Medical College. “Being over age 50 is the biggest risk factor. Other non-modifiable risk factors include a family history of AMD, and certain genetic predisposition factors, including variations in genes, such as the complement factor H gene, that is involved in the production of inflammatory responses.”
The most significant modifiable risk factor of AMD is smoking.
“Those who smoke or who have smoked have a several-fold increased risk of AMD, as well as an increased risk of progression to the late stages of AMD. Eating a high-fat diet also has been linked to the progression of AMD,” says Dr. Kiss.
WHAT YOU CAN DO
Include foods in your diet that
support vision health:
➤ Green, leafy vegetables (spinach, kale, Romaine and green leaf lettuce, collard greens).
➤ Foods rich in beta carotene, such as carrots, sweet potatoes, red peppers, cantaloupe, and winter squash.
➤ Foods that contain vitamin C, including oranges, grapefruit, strawberries, pineapple, and broccoli.
➤ Good sources of vitamin E, including sunflower seeds, almonds, and peanuts.
Two types of AMD
AMD damages the macula of the eye, which is a small area located near the center of the retina. A healthy macula allows clear, sharp vision of objects that are straight ahead, in the center of the visual field.
There are two types of AMD: dry and wet.
“Dry AMD refers to atrophy of the retina that occurs from the formation of drusen (waste products that form deposits underneath the retina), and pigmentary migration (an indication of retina damage). Wet, or exudative, AMD refers to the formation of abnormal blood vessels underneath the retina. The abnormal blood vessels leak fluid, bleed, and scar, which leads to vision impairment,” explains Dr. Kiss.
AMD typically progresses from the dry to the wet form; according to Dr. Kiss, the average age of patients with wet AMD is around 80.
Signs that indicate AMD may be present include blurred vision, areas of waviness in vi-sion, called metamorphopsia (where straight lines appear to be wavy due to the blood and fluid buildup from the abnormal blood vessels), and areas of missing vision in the central visual field, which are called scotomas.
However, in some people, AMD progresses slowly, and, in the early stages, there may be no symptoms, which is why it is so important to have regular eye exams.
“Early detection with frequent eye exams for people at risk (for example, those with a strong family history or known genetic predisposition) can help in the early treatment of AMD and prevention of severe vision loss,” notes Dr. Kiss.
If you have a strong family history of vision loss from AMD, Dr. Kiss recommends having a dilated retinal exam starting at age 50, or sooner, if you experience any of the symptoms described above. If no abnormalities are noted, then yearly exams are sufficient. If you have signs of dry AMD, then a completed dilated exam with ancillary testing should be done at least every six months.
“AMD is diagnosed by performing dilated fundus (retina) exams, along with special-ized testing, such as an optical coherence tomography (OCT). Specialized dye testing (flourescein angiography or indocyanine green angiography) may also be required,” says Dr. Kiss.
Prevention and treatment
Dr. Kiss says that smoking cessation is a must to lower the risk of developing AMD. He also advises eating a heart-healthy diet, with plenty of brightly colored fruits and vegetables and good sources of omega-3 fatty acids, such as salmon.
Progression of dry AMD may be slowed by taking AREDS supplements, which include antioxidants (vita-mins C and E, beta carotene, zinc, and copper) that have been shown to be effective against AMD in clinical trials. Treatment of wet AMD is via injection of medications, often monthly, to aid in the prevention of the leaking, bleeding, and scarring from the abnormal blood vessels.
Two medications, Eylea and Lucentis, are currently approved for treating AMD. A third medication, Avastin, is oftentimes used “off label.” It has been approved by the U.S. Food and Drug Administration for the treatment of colon and other cancers, but not for AMD.
“These three medications target a molecule called vascular endothelial growth factor, or VEGF, that is responsible for both the growth and leakage of the abnormal blood vessels under the retina. For many patients, multiple monthly injections are needed throughout many years,” explains Dr. Kiss. “The good news is that, with these injections, 95 percent of patients maintain their vision, and up to 40 percent actually improve. This is in stark contrast to the pre-injection era, when 100 percent of patients became legally blind within two years of a diagnosis of wet AMD.”
Researchers are attempting to develop more treatment options for AMD. New treatments in development include administering medication intravenously or via eye drops rather than directly into the eye. However, Dr. Kiss notes that these treatments are many, many years away from being approved for use by the FDA, if, in-deed, development progresses to that point.
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