It’s hard to read or watch TV. You can’t get a good look at others. And forget about driving! It’s no wonder that age-related macular degeneration (AMD) is such a devastating condition. It’s the leading cause of vision loss among older Americans. Hardening of the arteries that nourish the retina deprives that part of the eye of oxygen and nutrients, damaging nerve cells in the macula—a small area on the retina at the back of the eye—so that central vision deteriorates. The only good news about AMD is that it does not affect peripheral vision, so it does not result in total blindness. Eyeglasses cannot correct AMD, and in many cases, the macula’s breakdown creates a blank or dark spot in the central vision field.

What Exactly Is AMD?

There are two types of macular degeneration: “wet” and “dry.” Both dim and blur the center of one’s field of vision. However, the symptoms of dry macular degeneration develop so gradually that the person may not notice them, while wet macular degeneration changes vision so suddenly and dramatically that symptoms are obvious. Dry macular degeneration is the more common type, and it results in a less severe loss of vision. Wet macular degeneration involves the development of new blood vessels under the retina, a condition that causes hemorrhaging, swelling, and the development of scar tissue, all of which distort vision.

The main signs and symptoms of age-related macular degeneration are a loss of central vision, difficulty doing close work such as reading, sewing, or anything that requires attention to detail, and a wavy or bent distortion of objects that are straight, such as doorways or window edges. Routine eye exams detect macular degeneration by means of a visual acuity test that checks central vision and an ophthalmoscopy, which examines the retina and macula for signs of damage.

Conventional medicine considers both types of AMD progressive and irreversible. There is no conventional treatment for dry macular degeneration. Progress is being made in the laser treatment of wet macular degeneration to stop the abnormal growth of blood vessels in some patients, but laser treatment cannot restore lost vision: When successful, it only prevents further loss.

Because prevention is so important, researchers at the University of Pittsburgh spent 15 years looking for a gene linked to age-related macular degeneration. This gene’s discovery, announced in August 2005, is expected to lead to simple screening tests that will identify those most at risk.

Who’s at Risk?

The most obvious risk factor for AMD is age. Nearly 30 percent of Americans over 75 have early signs of AMD, and 7 percent have advanced symptoms. In contrast, only 8 percent of those aged 43 to 54 have early symptoms, and less than 0.1 percent show advanced macular degeneration. Other risk factors include gender (women are more likely to develop macular degeneration than men), family history, smoking, excessive sunlight exposure, obesity, and decreased dietary, serum, and tissue levels of lutein and zeaxanthin.

Can You Prevent AMD?

Lutein and zeaxanthin are carotenoids, pigments that give vegetables their bright colors. The lutein-zeaxanthin connection has holistic health practitioners excited because foods that contain them supply the macula with nutrients that can slow the progress of the disease. For example zeaxanthin works synergistically with antioxidant vitamins C and E to protect against oxidative damage.

Lutein and zeaxanthin occur in high amounts in kale, spinach, collard greens, and turnip greens, and in lower but significant amounts in lettuce, broccoli, sweet corn, green peas, and Brussels sprouts. Increasing your consumption of foods or supplements rich in these carotenoids can slow the progress of AMD. It also helps to quit smoking and to protect your eyes from excessive ultraviolet rays.

The Age-Related Eye Disease Study, a comprehensive investigation of supplements’ impact on AMD and vision loss, suggests that taking antioxidants (vitamins C and E, beta carotene, and the mineral zinc) daily can reduce progression to advanced AMD by 25 percent. One Wisconsin study also links an increased intake of omega-3–rich cold-water fish with reduced incidence of macular degeneration. By contrast, trans fat (hydrogenated or partially hydrogenated fat) appears to increase the risk for this condition.

Medicinal herbs may slow the development of macular degeneration, but for now most evidence supporting this approach is anecdotal. The herb that some call the brain’s best friend (it’s popular in Europe as a treatment for early-stage Alzheimer’s disease and in the U.S. as a memory tonic), Ginkgo biloba is often recommended for those at risk for AMD. A randomized trial of 20 patients showed that ginkgo had a beneficial effect on AMD. But because of the study’s small size, its results are considered equivocal. The herb is usually well tolerated, but if it’s taken in combination with blood-thinning medication, it may increase the risk of bleeding.

Growing Support

As public awareness of age-related macular degeneration grows, support groups and national organizations provide information and coping strategies (please see Selected Sources). Because of the increase in macular degeneration, there is a growing number of low-vision centers throughout the U.S. Low-vision specialists are trained to help those with AMD and similar conditions improve their quality of life by recommending appropriate magnifiers, reading aids, resources, and other support.

For example, a halogen light emits less glare than a conventional bulb and disperses light in a way that makes things easier for AMD patients to see. Shining the light directly on a page also lessens contrast and makes print easier to read. In addition, libraries and bookstores carry books printed in large type as well as audio books recorded on cassette tapes or CDs. Thanks to these special publications, even those with advanced AMD can keep up with the best-seller lists.

Test Yourself

The Amsler Grid is a popular tool for do-it-yourself testing (see the image at right). Distributed by doctors to help patients monitor changes in their vision, it’s a printed card with a circle in the center of a grid of straight lines. As AMD progresses, the straight lines may curve, bend, disappear, or blur.