macular degeneration
a group of conditions affecting the MACULA lutea of the eye, resulting in a reduction or loss of central vision. Age-related macular degeneration (AMD, ARMD) is the most common cause of blindness in the elderly. Two types are commonly recognized. Atrophic (or dry) AMD results from chronic choroidal ischaemia: small blood vessels of the choroid, which lies beneath the retina, become constricted, reducing the blood supply to the macula. This gives rise to degenerative changes in the retinal pigment epithelium (RPE; see RETINA ), clinically recognized by macular pigmentation and the deposition of DRUSEN . Wet AMD is associated with the growth of abnormal new blood vessels under the retina, derived from the choroid (see NEOVASCULARIZATION ). These can leak fluid and blood into the RPE, which further reduces macular function. Laser surgery (see PHOTOCOAGULATION ) can halt the degenerative process.
Macular degeneration, or age-related macular degeneration (AMD), is a leading cause of vision loss in Americans 60 and older. It is a disease that destroys your sharp, central vision. You need central vision to see objects clearly and to do tasks such as reading and driving.
AMD affects the macula, the part of the eye that allows you to see fine detail. It does not hurt, but it causes cells in the macula to die. There are two types: wet and dry. Wet AMD happens when abnormal blood vessels grow under the macula. These new blood vessels often leak blood and fluid. Wet AMD damages the macula quickly. Blurred vision is a common early symptom. Dry AMD happens when the light-sensitive cells in the macula slowly break down. You gradually lose your central vision. A common early symptom is that straight lines appear crooked.
Regular comprehensive eye exams can detect macular degeneration before the disease causes vision loss. Treatment can slow vision loss. It does not restore vision.
NIH: National Eye Institute
macular-degeneration