Thursday, April 9, 2009

Macular Degeneration

Macular degeneration is the progressive deterioration of a critical region of the retina called the macula. It is a medical condition usually of older adults which results in a loss of vision in the center of the visual field because of damage to the macula. It occurs in “dry” and “wet” forms.

The retina is the inner layer of the eye; it contains nerves which transmit light stimulus. The choroid is another layer behind the retina; it contains the blood supply to the retina. In the dry form, nonexudative, cellular debris called drusen build up between the retina and the choroid, and the retina can become detached. In the wet form, exudative, which is more severe, blood vessels grow up from the choroid's Bruch's membrane behind the retina, which becomes detached and loose. It can be treated with laser coagulation, and with medication that stops and sometimes reverses the growth of blood vessels.

Macular degeneration is a common cause of blindness in people over 60, and accounts for approximately 11.7% of blindness in the United States. About 28% of the population over age 74 is affected by this disease.