Age-related macular degeneration (AMD) is a medical condition which usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of blindness and visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life.
Starting from the inside of the eye and going towards the outer surface, the three main layers at the back of the eye are the retina, which is light-sensitive tissue that is considered part of the central nervous system and is actually brain tissue; the choroid, which contains the blood supply; and the sclera, which is the white, outer, layer of the eye.
The macula is the central area of the retina, which provides the most detailed central vision.
In the dry (nonexudative) form, cellular debris called drusen accumulates between the retina and the choroid, and the retina can become detached. In the wet (exudative) form, which is more severe, blood vessels grow up from the choroid behind the retina, and the retina can also become detached. It can be treated with laser coagulation, and with medication that stops and sometimes reverses the growth of blood vessels.