Macular degeneration is a painless, degenerative eye disease that affects more than 10 million Americans. It is the leading cause of legal blindness in persons over the age of 55 in the United States. While complete blindness does not occur in most people with the disorder, macular degeneration often interferes with reading, driving, or performing other daily activities.

There are two forms of macular degeneration. Dry macular degeneration affects about 90% of those with the disease and causes gradual loss of central vision, initially only in one eye. Wet macular degeneration, which accounts for 90% of all severe vision loss from the disease, involves a very sudden loss of central vision.

Macular degeneration is accompanied by the following signs and symptoms:

• Slightly blurred vision
• Dry type: a blurred spot in the central field of vision, which may become larger and darker
• Wet type: straight lines that appear wavy and the rapid loss of central vision; sometimes, wet macular degeneration starts with a sudden blind spot

Dry macular degeneration occurs from the breakdown of the light sensitive cells in the center of the retina, called the macula. Wet macular degeneration occurs when new blood vessels behind the retina grow toward the macula and leak blood and fluid.

People with the following conditions or characteristics are at risk for developing macular degeneration:

• Age—the risk increases with age
• Cigarette smoking
• Family history of macular degeneration
• Cardiovascular disease
• Elevated levels of cholesterol
• Light eye color
• Excessive exposure to sunlight

Your eye care professional can detect macular degeneration during an eye examination that includes the following:

• Testing with an eye chart to measure your ability to see at various distances.
• Pupil dilation—drops are placed in your eyes to widen the pupils and reveal more of the retina.
• Checking for presence of drusen (tiny yellow deposits in the retina).
• Testing with Amsler's grid, which involves covering one eye and staring at a black dot in the center of a checkerboard-like grid. If the straight lines in the pattern appear wavy or some of the lines appear to be missing, these may be signs of wet macular degeneration.
• Fluorescein angiography—a special dye is injected into a vein in the arm and pictures are taken as the dye passes through the blood vessels in the retina.

If you have wet macular degeneration, you will test your eyes daily at home using an Amsler's grid. You should report any distortion immediately to reduce the risk of vision loss. Other preventive measures include increasing your dietary intake of flavonoids and carotenoids (see section on Nutrition), using ultraviolet eye protection, estrogen replacement therapy, and moderate red wine consumption.

There is no known cure for macular degneration; however, there are procedures that can help slow vision loss.

Your provider may prescribe the following medications:

• Tissue plasminogen activator (tPA)
• Thalidomide (an investigational therapy)

Surgical and other procedures may be beneficial for some cases of wet macular degeneration.

• Laser surgery—a high-energy beam of light is aimed directly at the leaking blood vessels to seal them off
• Photodynamic therapy—photosensitized tissue is irradiated with a low-powered laser light
• Vitrectomy—removes newly formed blood vessels and blood underneath the retina if performed within 7 days of bleeding

Nutrition is a valuable treatment for dry macular degeneration. It may also help prevent both wet and dry types related to aging.

Antioxidants that protect your retina—such as carotenoids, selenium, zinc, and vitamins C and E—may delay or prevent macular degeneration. Some studies have shown that these nutrients help, but not all studies agree. In one study of 356 patients with advanced macular degeneration, diets high in carotenoids lowered risk for the condition. Two particular carotenoids, lutein and zeaxanthin, had the greatest effect; results also suggested that dietary vitamin C may be beneficial for prevention of macular degeneration as well. Three large studies, however, found no connection between macular problems and dietary or supplementary intake of carotene, zinc, or vitamins A, C, and E.

Other research reviews, which summarize data from several studies, suggest that eating a diet high in vitamins C and E and carotenoids may reduce your risk of macular degeneration. Vegetables rich in carotene include orange and yellow squash, and dark, leafy greens, such as kale, collards, spinach, and watercress. Although the scientific information is somewhat conflicting about supplements in particular, eating a diet rich in the nutrients mentioned above may be effective in preventing macular degeneration.

If, with the advice of your healthcare provider, you decide to take supplements, the following are some suggested amounts of key nutrients:

• Mixed carotenoids, 25,000 to 50,000 International Units (IU) a day
• The carotenoid lutein, 5 milligrams (mg) a day
• Selenium, 200 to 500 micrograms (mcg) a day
• Zinc, up to 50 mg a day
• Vitamin C, 60 to 2000 mg a day in divided doses; doses over 1000 mg a day may cause gastrointestinal problems, including nausea and diarrhea
• Vitamin E, 50 to 1000 IU a day (usually 400 to 800 IU a day)

Flavonoids (such as quercetin, rutin, and resveritrol) may also play a role in preventing macular degeneration. A study of 3,072 adults with macular changes showed that moderate red wine consumption may offer some protection against the development or progression of macular degeneration. Red wine is high in certain flavonoids (including quercetin, rutin, and resveritrol) that have antioxidant activity; damage from oxidative stress is thought to contribute to the development of macular degeneration. Dark berries, such as blueberries, blackberries, and dark cherries, are high in flavonoids as well.

Omega-3 fatty acids may also offer some protection against macular degeneration. In a study of more than 3000 people over the age of 49, those who consumed more fish in their diet were less likely to have macular degeneration than those who consumed less fish. (Most types of fish are rich in omega-3 fatty acids). Similarly, a study comparing 350 people with macular degeneration to 500 without found that those with a proper ratio of omega-3 to omega-6 fatty acids and higher intake of fish in their diets were less likely to have this particular eye disorder. Another larger study found that consuming docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), two types of omega-3 fatty acids found in fish, four or more times per week may reduce the risk of developing macular degeneration. Notably, however, this same study suggests that alpha-linolenic acid (ALA; another type of omega-3 fatty acid) may actually increase the risk of this eye condition.

Ginkgo (Ginkgo biloba), which contains flavonoids, may help halt or lessen some retinal problems. Clinical studies suggest that it may be useful in treating vision problems specifically due to macular degeneration. If you use anticoagulants, do not use ginkgo without close monitoring by your healthcare provider.

Bilberry (Vaccinium myrtillus) and grape seed (Vitis vinifera) are also high in flavonoids; therefore, they may help prevent and treat macular degeneration. Clinical studies suggest that these herbs may stop vision loss and improve visual sharpness. Here are the recommended doses:

• Ginkgo standardized to 24%, 120 mg once or twice a day
• Bilberry extract standardized to 25%, 120 to 240 mg twice a day
• Grape seed, 50 to 150 mg once or twice a day

Although scientific research does not necessarily support the use of homeopathy to treat or prevent macular degeneration specifically, an experienced homeopath would consider your individual case to decide whether treatment may be beneficial for you.

Studies on acupuncture and macular degeneration have been mixed. In a study of 51 patients with macular problems, researchers found little change in visual sharpness or other symptoms after 12 acupuncture treatments. Another study showed a connection between low blood flow to the head and macular degeneration. Restoring normal blood pressure with acupuncture improved vision.

Blindness is a possible outcome of macular degeneration. Low vision aids may help if you have partial blindness. Sometimes blood vessels build up underneath the retina, causing the retina to become detached or scarred. If this happens, the chances of preserving your central vision are poor. This condition, called subretinal neovascularization, occurs in about 20% of cases of age-related macular degeneration. The condition will likely recur even after laser treatment.

Your healthcare provider will see you regularly to monitor your vision and eye health.

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