Age-related macular degeneration (AMD) is the leading cause of vision loss in Americans over age 60, and presents in two forms: Dry Macular Degeneration and Wet Macular Degeneration. Of the two, the “dry” form is far more common, but both affect the center region of the retina called the macula which is responsible for processing the fine details we see.
Neovascular refers to growth of new blood vessels in an area, such as the macula, which can cause vision loss.
Dry Macular Degeneration (Non-Neovascular)
Dry AMD is more widespread and more difficult to treat. In dry AMD, the layers of cells beneath the retina in the macula stop functioning properly. This may result from the aging and thinning of macular tissues, depositing of pigment in the macula, or a combination of the two processes. People with dry macular degeneration often have holes or blank areas in their central vision that can worsen over time. When the doctor views the back of the eye yellowish spots, called Drusen may be visible in the macula. Drusen are believed to be deposits or debris from deteriorating macular tissue.
Wet Macular Degeneration (Neovascular)
Wet AMD is more serious and far less common. In about 10% of cases, dry AMD progresses to wet macular degeneration.
Neovascular refers to growth of new blood vessels in an area, such as the macula, where they are not supposed to be. These new, defective blood vessels grow beneath the retina where they eventually leak and bleed. The abnormal blood vessel growth in wet AMD is the body’s misguided attempt to create a new network of blood vessels to supply more nutrients and oxygen to the macula. But, the process instead creates scarring and central vision loss.
Wet AMD causes a more rapid loss of vision, sometimes leading to blindness within weeks. This requires the intervention by an experienced ophthalmologist.
No matter which form of macular degeneration you have, it is important to be seen by a doctor as soon as possible to preserve vision.