Macular Degeneration

Basic Facts

Age-Related Macular Degeneration

Age-related macular degeneration (ARMD) is a disease that damages part of your retina. The retina is 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, see road signs or traffic signals while driving a car, or watch television or a movie. ARMD damages your macula.

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. About 30% of those older than 75 have ARMD.  Age-related macular degeneration usually doesn’t affect your peripheral vision.

There are two types of ARMD:

  1. Dry ARMD
    Dry age-related macular degeneration is the more common of the two types. It accounts for 80 to 90 percent of all cases of macular degeneration. With dry ARMD, fatty yellow deposits called drusen develop under the retina. This causes the macula to become thinner and begin to lose function.  As a result, someone with dry ARMD may see a dark, blurry spot, or a blank spot, in the middle of their visual field. Vision loss due to dry ARMD is slow and gradual.

    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 are diagnosed with either form of ARMD.

    According to the American Academy of Ophthalmology, people with dry ARMD should monitor their central vision by 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.

  2. Wet ARMD 
    Wet age-related macular degeneration accounts for 10 to 20 percent of all cases of ARMD. With this type of macular degeneration, two changes occur. The first is that fatty yellow deposits called drusen accumulate. The second is that abnormal blood vessels begin to grow under the retina (this is known as CNV, or choroidal neovascularization). The accumulation of drusen alone does not cause vision loss, but the accompanying blood vessel leakage causes damage. Wet ARMD can cause rapid and severe vision loss and central visual blindness. Early diagnosis is extremely important in order to determine whether treatment would prevent irreversible loss of vision.

 

Last Updated March 2017