Until recently, there was no way to prevent age-related macular degeneration (ARMD) or halt the disease's gradual—but nevertheless persistent — deterioration of the eye's light-sensitive retina.
Good news: The most current research confirms that a healthful diet and prudent lifestyle choices can reduce your risk of developing ARMD. What's more, new treatments are highly effective at minimizing vision loss in the early stages of the disorder.
WHO'S AT RISK?...
ARMD affects one in three Americans over age 65. In its mildest form, the condition results in blurred vision and difficulty reading. But it can quickly progress to a more advanced form that causes blindness.
The disorder affects the macula, the region of the retina that's responsible for "central vision." This enables us to read, recognize faces, drive and perform other activities that require sharp vision.
Most cases of macular degeneration begin with the formation of drusen — tiny yellow deposits that grow just behind the macula.
Known as "dry" ARMD, this condition can persist for years, usually causing only minor vision problems.
Unfortunately, one in 10 of those who are diagnosed with dry ARMD go on to develop "wet" ARMD. This form occurs when blood vessels under the retina leak fluid and form scar tissue, damaging or distorting the smooth surface of the retina. Wet ARMD can rob a person of central vision.
RISK-REDUCTION STRATEGIES...
Researchers have now identified several factors that contribute to macular degeneration. To curb your risk for this disorder...
Give up smoking. Studies show that smoking is the most significant risk factor for ARMD.
Minimize your exposure to sunlight. Wear sunglasses with amber-colored lenses that block blue-violet light and 100% of UVA and UVB rays. They can be purchased at any good eyeglass store.
Follow a heart-healthy regimen. The same factors that increase heart disease risk — especially high blood pressure and high cholesterol intake — heighten your risk for ARMD.
To protect your heart and eyes: Cut back on saturated fat...get regular exercise...and have your blood pressure checked at least once a year.
Eat plenty of leafy green vegetables. Spinach, collard greens and kale contain the carotenoids lutein and zeaxanthin, which are believed to help fight ARMD. Eat at least five one-cup servings of these vegetables each week.
EARLY DETECTION...
For anyone over age 55, the best defense against ARMD is an annual eye exam by an ophthalmologist. If a parent or sibling has ARMD, have annual eye exams beginning at age 40.
See an ophthalmologist immediately if printed text appears blurry...straight edges of doorways or windows appear wavy...or if a dark —or blank— spot obstructs the center of your vision.
During the eye exam, your doctor will use a handheld lighted instrument (ophthalmoscope) to check for drusen. Fluid under the retina can be a sign of wet ARMD, which requires treatment and evaluation from an ophthalmologist who specializes in disorders of the retina.*
Your doctor should also test your eyesight using an Amsler grid, a chart with lines that resemble graph paper. If lines appear wavy when you focus on a dot in the center of the grid, you may have wet ARMD.
*To find a retinal specialist in your area, contact the American Academy of Ophthalmology at 415-561-8500, www.aao.org.
TREATMENTS...
A number of treatments are now available to reduce the blood vessel damage associated with wet ARMD...
Laser therapy is an effective way to stop the progression of ARMD. During this 30-minute outpatient procedure, a high-powered laser seals off the leaky blood vessel.
Laser therapy is recommended if the blood vessel is clearly visible and located to the side of the retina. This allows the ophthalmologist to control any vision loss that can result from tissue damage caused by the laser therapy.
Photodynamic therapy (PDT), a promising new form of laser therapy that uses a photo-sensitive dye, is available at many teaching hospitals. It causes less tissue damage than traditional laser therapy. For this reason, PDT is the preferred treatment. However, it must be repeated every few months.
For a list of medical centers that perform PDT, go to the Novartis Ophthalmics website at www.visudyne.com/aboutv/centers.html
Clinical trials are also being held to determine the effectiveness of other new treatments.
Submacular surgery removes the blood vessel through a hole in the side of the retina. This procedure is being tested on patients whose damaged blood vessel is located in the center of the retina, which diminishes the success of laser surgery.
Transpupillary thermo-therapy uses a low-temperature laser, which limits damage to the retina and surrounding tissue.
Radiation therapy uses a beam of electromagnetic energy to destroy leaky blood vessels in much the same way that radiation is used to treat cancer. However, results from current trials have not shown a large benefit from radiation therapy.
Antiangiogenesis drugs block the proteins that are critical to the formation of blood vessels that lead to ARMD.
For more information on clinical trials, contact the National Eye Institute, 301-496-5248, www.nei.nih.gov
source: Robert D'Amato, MD, PhD, associate professor of ophthalmology at Harvard Medical School, and an attending physician at the Massachusetts Eye and Ear Infirmary, both in Boston. He is coauthor of Macular Degeneration—The Latest Scientific Discoveries and Treatments for Preserving Your Sight. Walker & Co.
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