What Is Age Related Macular Degeneration (Wet or Dry) and What Causes It?
What Is Age Related Macular Degeneration (AMD)?
Macular degeneration is what happens when a small central portion of the retina, known as the macula, starts deteriorating. The retina is the light-sensing nerve tissue at the back of the eye. As the disease develops as a person starts aging, it’s usually known as age-related macular degeneration (AMD). While macular degeneration is virtually never a totally blinding condition, it can be a source of significant visual disability.
What Causes AMD?
The delicate cells of the macula can sometimes become damaged and stop working. While it certainly seems like a kind of nutritional deficiency that can occur at any age, it tends to happen the most as people get older—which is why it’s known as age-related macular degeneration.
AMD is the most common cause of poor sight among those over the age of 60. While it never leads to 100% sight loss, it may result in only 5% peripheral or side vision.
There are two main types of age-related macular degeneration:
- Dry AMD: Around 90% of people diagnosed with AMD have dry degeneration. It occurs when the cells of the macula become malnourished and start to waste away, meaning that these cells can no longer function properly. Dry AMD is also called non-exudative AMD.
- Wet AMD: This is less common (10% of cases) and occurs when tiny blood vessels grow between the retina and the back of the eye when blood flow is failing—again, from some sort of malnourishment or cardiovascular disease. These blood vessels leak and bleed as they grow, causing scarring of the macula. Wet AMD is also known as exudative or disciform degeneration.