The macula is a part of the retina in the back of the eye that ensures that our central vision is clear and sharp. Age-related macular degeneration (AMD) occurs when the arteries that nourish the retina harden. Deprived of nutrients, the retinal tissues begin to weaken and die, causing vision loss. Patients may experience anything from a blurry, gray or distorted area to a blind spot in the center of vision.
AMD is the number-one cause of vision loss in the U.S. Macular degeneration doesn't cause total blindness because it doesn't affect the peripheral vision. Possible risk factors include genetics, age, diet, smoking and sunlight exposure. Regular eye exams are highly recommended to detect macular degeneration early and prevent permanent vision loss.
Symptoms of macular degeneration include:
- A gradual loss of ability to see objects clearly
- A gradual loss of color vision
- Distorted or blurry vision
- A dark or empty area appearing in the center of vision
There are two kinds of AMD: wet (neovascular/exudative) and dry (non-neovascular). About 10-15% of people with AMD have the wet form. "Neovascular" means "new vessels." Accordingly, wet AMD occurs when new blood vessels grow into the retina as the eye attempts to compensate for the blocked arteries. These new vessels are very fragile, and often leak blood and fluid between the layers of the retina. Not only does this leakage distort vision, but when the blood dries, scar tissue forms on the retina as well. This creates a dark spot in the patient's vision.
Dry AMD is much more common than wet AMD. Patients with this type of macular degeneration do not experience new vessel growth. Instead, symptoms include thinning of the retina, loss of retinal pigment and the formation of small, round particles inside the retina called drusen. Vision loss with dry AMD is slower and often less severe than with wet AMD.
Recent developments in ophthalmology allow doctors to treat many patients with early-stage AMD with the help of lasers and medication.