The retina is the tissue that lines the back of the eye. It sends visual signals to the brain. The macula is part of the retina.
Macular degeneration is a chronic and usually progressive disorder that affects the central part of the retina (the macula) and reduces the ability to see. Macular degeneration causes a gradual loss of sharp, central vision.
Macular degeneration is the leading cause of blindness in older adults in the US. The frequency of this disorder increases with age. The majority of affected people are over 75-80 years old. In rare cases, it can occur in younger people.
Adult macular degeneration (AMD) is the most common form of macular degeneration.
There are 3 stages of AMD, depending on the presence and size of drusen (yellow deposits beneath the retina), pigment changes in the retina, the amount of macular damage, and severity of visual changes.
Early Macular Degeneration
There are medium-sized drusen (about the width of an average human hair), but no macular changes or vision loss.
Intermediate Macular Degeneration
There are large drusen, pigment changes in the retina, or both, some vision loss, but no macular changes or other symptoms.
Late Macular Degeneration
In addition to drusen and pigment changes, there is more severe vision loss and macular changes.
Dry (geographic) AMD is most common and involves macular thinning due to a slow breakdown of cells in the macula.
Wet (neovascular) AMD also includes abnormal blood vessels that grow under the retina and macula. This can result in macular damage from pressure or bleeding and fluid leakage.