Don’t lose sight: macular degeneration can rob you of your vision, but a newly approved drug could help preserveand even improveyour sight
You’re having trouble reading. People’s faces are difficult to distinguish. Objects look wavy or blurry. You may have age-related macular degeneration (AMD), the leading cause of blindness in people over 55. The disease causes damage to the retina, the lining in the back of your eye that helps send images to your brain. The macula consists of cells in the center of the retina that account for your detailed “straight-ahead vision”–the vision you use for reading and driving.
There are two types of AMD. The dry form occurs when cells that feed the retina deteriorate or stop functioning properly. Over time, dry AMD causes blurring of central vision. The wet form–the more serious type–is due to abnormal blood vessels under the retina. These abnormal vessels can bleed or leak fluid, rapidly decreasing vision. In most cases, scarring occurs, resulting in permanent loss of central vision.
Until recently, treatments only stopped AMD from getting worse. But a newly approved drug called ranibizumab (Lucentis) is promising to be a sight for sore eyes for patients with wet AMD.
“The drug not only stabilizes the disease, but can actually improve vision, too,” says Robin Ginsburg, MD, professor of ophthalmology at the Mount Sinai School of Medicine.
Lucentis is a vascular endothelial growth factor (VEGF) inhibitor or anti-VEGF, a drug that blocks the growth of new blood vessels in the back of the eye. Lucentis is the first drug to show improved vision in a significant number of patients. In clinical trials, up to 40 percent of people taking Lucentis for a year had improved vision, meaning they could read more letters or lines on an eye exam chart. Dr. Ginsburg says that Lucentis appears to work on more forms of wet AMD than currently available treatment options.
Macugen, another anti-VEGF drug already approved for the treatment of AMD, also offers promise for slowing the progression of AMD.
But, there are downsides to these sight-saving drugs. Both Lucentis and Macugen must be given by a shot directly into the eye, about once every 4 to 6 weeks. Side effects may include eye swelling and pain, specks or clouds in front of the eye (floaters), cataract, detachment of the retina, and a serious eye infection.
Shining light on the situation
Because of the expense (one injection of Lucentis can cost $1,950) and unpleasant injections associated with anti-VEGFs, Dr. Ginsburg says many people with wet AMD are still treated with lasers.
Thermal laser therapy uses a hot beam of light to destroy abnormal blood vessels. “It’s usually a one-shot deal, and it works,” Dr. Ginsburg says. “Vision usually won’t improve, but it won’t get worse.” The therapy creates a slight blind spot in the eye, but most people don’t notice it. The procedure is best for those who have leaking vessels away from the central part of the retina.
Photodynamic therapy (PDT) uses a cold laser to “turn on” a drug, which is injected into your arm. The drug sticks to new blood vessels. When the doctor shines the laser beam on the eye, the drug seals the leaking vessels without damaging the retina. PDT only temporarily slows vision loss–patients usually need more than one treatment. And it also only works on a small subgroup of patients with wet AMD.
Are you at risk?
No one knows exactly why one person gets AMD and another doesn’t. However, the disease tends to be more common in people who smoke, have fair skin, high blood pressure, or a family history of the disease.
Genes may play a role: A study in the July Journal of the American Medical Association suggested that a genetic mutation called CFH Y402H might be involved in more than 50 percent of AMD cases. The study also found that smoking and elevated levels of C-reactive protein (a marker of inflammation) further increased the AMD risk in people with this genetic variation.
Can you prevent AMD?
The most important thing you can do to help prevent permanent vision loss is to get eye exams once a year, or more if you have eye problems. Straight lines that appear wavy are often the first sign of wet AMD. Don’t consider these or other vision problems a normal part of aging. The earlier AMD is discovered, the better chance you can save your vision.
There is no known way to prevent AMD, but lifestyle changes can help reduce your risk. Wear sunglasses to reduce sun damage to your eyes. If you smoke, stop. Eat a heart-healthy diet, rich in colorful fruits, green leafy vegetables, and fish. A study in the July 2006 Archives of Opthalmology found that seniors who ate fish at least twice a week were about half as likely to develop AMD as those who did not.
WHAT YOU CAN DO
To help you adjust to life with AMD:
* Talk to your doctor about vision rehabilitation. Such therapy can help you learn new ways to do everyday tasks such as cooking or reading the newspaper. For more information, visit: www.healthyvision2010.org
* Use magnifying glasses or a magnifier to enlarge print in books and newspapers. Large-print books and newspapers, as well as audiobooks, are also available.
* Adjust your computer screen to make the font bigger.
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