What is Macular Degeneration?
Macular degeneration is a disorder that occurs when the small central portion of the retina, known as the macula, deteriorates, leading to severe vision loss. The retina is the nerve tissue at the back of the eye, which senses light and any deterioration or damage to it results in partial or total loss of vision. It is the leading cause of vision loss in people over the age of 60 years. It is also known as age-related macular degeneration or AMD because it develops in older people as they age.
There are two types of age-related macular degeneration. They are the dry form and the wet form. The dry form of macular degeneration is caused by deposits of a yellow substance known as ‘drusen’ in the macula. A few drusen deposits may not affect vision, but with increasing size and number they can distort or cause a dimming of vision that is usually apparent when the affected person is reading. Advanced cases of dry AMD can also result in a thinning of the light sensitive nerve tissue leading to tissue death which causes blind spots in the center of a person’s vision.
The wet form of macular degeneration is caused by an abnormal growth of blood vessels in the area underneath the macula, also known as choroidal neovascularization. These blood vessels leak blood and fluid into the retina resulting in distorted vision and loss of central vision. Scarring can also lead to a permanent loss of central vision. It is a rarer form of AMD, affecting about 10% of all cases but is the more damaging of the two.
Alternative Names: Age-related macular degeneration; AMD; central geographic atrophy; dry AMD; neovascular AMD; exudative AMD; wet AMD