Aging & Health A to Z
Basic Facts & Information
What is age-related macular degeneration?
Age-related macular degeneration (ARMD) is a disease that damages part of your retina, the layer of cells, nerves, and blood vessels behind your eyes that sends images to your brain so you can see.
At the center of each retina is a small area called the macula. While the rest of the retina provides you with side vision (peripheral vision), the macula provides central vision, so you can see straight ahead. Your macula also enables you to see details. You use your macula when you read, recognize a face, drive a car to see roads signs or traffic signals, or watch television or a movie. ARMD damages your macula.
Age-related macular degeneration (ARMD) is the leading cause of permanent central vision loss in people 65 and older in developed countries. As the name suggests, ARMD increases with age. Roughly 2% of people in their 50s have ARMD, compared with 30% of those older than 75. Age-related macular degeneration usually doesn’t affect your peripheral vision.
There are two types of ARMD, a dry form and a wet form.
Dry age-related macular degeneration is the more common of the two types and accounts for 80 to 90 percent of all cases of macular degeneration. With dry macular degeneration, fatty yellow deposits called drusen develop under the retina, and the macula becomes thinner, and begins to lose function. As a result, someone with dry ARMD may see a dark, blurry spot, or a blank spot, in the middle of his or her visual field. Vision loss due to dry ARMD is slow and gradual, and isn’t as severe as wet ARMD.
Dry ARMD can progress to wet ARMD—which can cause rapid and more extensive damage and vision loss. You should be under the care of an eye specialist (ophthalmologist) if you re diagnosed with either form of ARMD.
According to the American Academy of Ophthalmology, people with dry ARMD should monitor their central vision daily, using a special, graph paper-like chart called an “Amsler grid.” If any part of the grid appears wavy, blurry, or dark—or if your vision is suddenly distorted—you should contact your ophthalmologist immediately. These changes could be a sign that you have developed wet ARMD.
Wet age-related macular degeneration accounts for 10 to 20 percent of all cases of age-related macular degeneration. With this type of macular degeneration, two changes occur; drusen (fatty yellow deposits) accumulates and abnormal blood vessels begin to grow under the retina. The accumulation of drusen alone does not cause vision loss, but the accompanying blood vessels leakage causes damage. Wet ARMD can cause rapid and severe vision loss and central visual blindness. Early diagnosis and treatment are extremely important and essential to treating ARMD.
Updated: March 2012
Posted: March 2012