What is AMD?
Age-related macular degeneration is a leading cause of vision loss in older patients. It results in the loss of central vision (the macula) due to damage to the retina and the support structures of the retina. There are two forms of macular degeneration: “wet” and “dry”.
The most common type is the “dry” type of macular degeneration. This type of macular degeneration occurs as the result of many different factors including aging, genetics, and a variety of environmental factors. Most people with “dry” macular degeneration are relatively asymptomatic however a few patients can lose significant vision from the “dry” form. The most common examination finding associated with “dry” AMD is that of drusen. Drusen are yellowish deposits of cellular debris that accumulate beneath the retina. In addition to drusen, pigmentary changes and atrophy (or loss of tissue beneath the retina) can develop. A dilated examination of the retina can detect the presence of drusen, pigmentary changes, and atrophy. Importantly, a dilated retinal examination by a retina specialist (an ophthalmologist who further specializes in evaluating and treating the retina) can not only detect these changes but can also help assess the risk of progression to advanced AMD.
Dry (Non-Exudative) Macular Degeneration
The dry form of macular degeneration is characterized by the formation of drusen beneath the retina. Drusen are yellowish deposits consisting of cellular debris. Drusen can be classified based on their appearance, size, location and along with the presence of pigmentary changes can help to determine the risk for progressing to advanced AMD.
Wet (Exudative) Macular Degeneration
The wet form of macular degeneration occurs when blood vessels grow irregularly beneath the retina. These blood vessels often will “leak” (hence the term wet or exudative) or bleed resulting in significant vision loss. Patients will often notice distortion or blurred vision as these vessels develop. Bleeding can result in a dark spot (or scotoma) in the central vision. If recognized early in the process, these blood vessels can be treated often with some recovery of vision. In some cases the blood vessels can form a scar or the leakage can damage the retina resulting in a more limited chance for improvement in vision.