What is age-related macular degeneration?
Age-related macular degeneration (AMD) is a disease of the central retina, which is called the macula. The retina is the tissue at the back of the eye that transmits images to the brain. The degeneration of cells in the macula affects the ability to see straight ahead. It's the straight-ahead, or central, vision that allows us to have really clear sight. It allows us to see sharp detail, to read, to drive, to see people's faces. AMD does not typically affect the peripheral vision, or side vision.
What are the different types of the condition?
There are two types of AMD: dry and wet. About 90 percent of the people with macular degeneration have the dry form of the disease. In this form, there is a slow breakdown of the light-sensitive cells in the macula. This condition may take years to develop, and people usually lose vision very slowly. It often happens in one eye and then may go to the other eye.
The wet form, though less common, is the version of the disease that can cause major loss of vision. It occurs when new blood vessels behind the retina start to grow towards the macula. These new blood vessels are very weak and they can start to leak or bleed. This damages the macula and causes rapid vision loss.
What are the risk factors for the condition?
The biggest risk factor is advanced age, so the older we get the more at risk we are. It affects about 20 percent of people aged 65 and older, and about 30 percent of people aged 74 and older.
