Macular degeneration is the physical disturbance of the center of the retina known as the macula. The macula is the part of the retina which enables acute and detailed vision. The macula is used for reading, driving, recognizing faces and watching television. Macular degeneration is the leading cause of legal blindness in people over age 55. Surgery to remove the scar produced by macular degeneration has been successful in younger patients but less successful in older patients.
Age-Related Macular Degeneration
Age-Related Macular Degeneration (AMD) is a common eye disease that affects a tiny area in the center of the retina known as the macula. The macula is made up of millions of light-sensing cells that help to produce sharp central vision. AMD breaks down these cells gradually destroying central vision.
It is estimated that over 13 million Americans over the age of 40 show early signs of AMD, and it is the leading cause of legal blindness and vision impairment in the senior population.
AMD occurs in two forms – wet and dry – with women being at a higher risk for developing one type than men. Smokers, people with light colored eyes, and individuals with a family history of AMD are also at risk for developing this condition.
Dry AMD – 90 percent of individuals diagnosed with AMD have the dry form. Light sensitive cells in the macula slowly break down, affecting central vision over time. Dry AMD often occurs in just one eye at first, and doctors have no way of knowing when or if both eyes will be affected.
Wet AMD – Although only ten percent of all people with AMD have this type, it accounts for 90 percent of all blindness. New blood vessels behind the retina begin to grow toward the macula. These vessels are very fragile and often leak blood and fluid under the macula, rapidly causing the damage that leads to loss of central vision.
What causes AMD?
Both genetic predisposition and environmental insults are responsible for development of AMD. We know that smoking makes it worse and exposure to UV radiation may also play a role in some patients; therefore we encourage patients to stop smoking and to wear UV blocking sunglasses.
What are the symptoms?
The most common symptoms of dry AMD are slightly blurred vision. As the disease progresses, a blurred spot forms in the center of your vision gradually becoming larger and darker, reducing central vision. Straight lines that appear wavy are an early sign of wet AMD. This is often followed by rapid loss of central vision. As in AMD, you may also notice a blind spot. Neither dry nor wet AMD causes any pain.
How is AMD Diagnosed?
AMD is detected during a comprehensive eye examination during which your doctor will examine the health of your retina. Once detected, your doctor may recommend additional testing to assess the type and progression of the disease to determine treatment.
What are the treatment options?
Currently, there is no treatment for dry AMD, but this does not mean you will lose your vision. Dry AMD develops very slowly over many years and most people are able to lead normal, active lives, especially if the disease affects only one eye. Wet AMD is treated with intraocular injections of anti-VEGF, a chemical mediator that helps to "dry up" the leaking blood vessels.