Macular Degeneration

Age-related macular degeneration (AMD or ARMD) is the leading cause of legal blindness in people over the age of 60 in the United States. The term “macula” refers to the central part of the retina, which is the back, inner lining of the eye. The retina, similar to film in a camera, captures light and sends signals to the optic nerve. The macula allows us to see in detail, recognize faces, read, drive and watch TV. In age-related macular degeneration, the macula is damaged, resulting in poor central vision. Because the peripheral retina is not involved, AMD cannot lead to total blindness.
Graphical representation of a scene as viewed by an individual with normal vision

Graphical representation of a scene as viewed by an individual with AMD

Age-related macular degeneration has two main types: dry and wet. The dry, or atrophic, type is most common, occurring in 80 to 90 percent of AMD patients. In the dry type, drusen, which is small, yellow deposits, builds up under the retina, indicating retinal pigment epithelium (RPE) changes. Dry AMD results in mild to moderate vision loss. The wet, or neovascular, type occurs in 10 to 20 percent of AMD patients, and can result in more significant vision loss. It results from new blood vessel growth under the retina, which can leak and cause fluid and/or blood to build up in the macula.

As its name states, the most common risk factor for age-related macular degeneration is aging. In general, AMD tends to be more common in females and Caucasians with light eye color. Genes also play an important role in determining risk level for AMD, as well as smoking and drug use.

Treating AMD
Patients with wet macular degeneration can be treated with injections, lasers or surgery, often with preservation of good vision. For patients diagnosed with dry macular degeneration, preventive measures that can slow progression include avoiding ultraviolet light by wearing protective sunglasses when outdoors, taking certain nutritional supplements and monitoring subtle vision changes using a square grid called an Amsler grid.