Age-related Macular Degeneration (AMD) is the most common cause of vision loss among the elderly. At the back of the eye is a thin layer of tissue called the retina. The macula is a small spot on the retina which provides detailed central vision. Degeneration of the macula results in blurry central vision.
There are two types of AMD: dry and wet. The dry form of the condition develops and progresses slowly. Wet AMD can develop quickly and causes more severe vision loss. Abnormal blood vessels develop and leak blood into the retina. Without treatment, loss of vision occurs rapidly.
What are the causes?
AMD is associated with the aging process but smoking, family history, high blood pressure, high cholesterol, obesity, diabetes and life long exposure to sunlight may also contribute to developing the condition.
What are the signs?
- Blurred vision
- Central shadows or missing areas of vision
- Distorted vision (wavy lines)
- Trouble distinguishing colors and facial features
- Difficulty adjusting from bright to dim light
How is it diagnosed?
An ophthalmologist can verify AMD by doing a fluorescein angiogram or an optical coherence tomography test (OCT). Individuals may be taught to use an Amsler Grid at home to monitor their vision.
How is it prevented?
Routine eye examinations are the best way to monitor eye health. There are products on the market that claim to prevent AMD. Ask your eye doctor whether these are recommended for you.
How is it treated?
There are a variety of treatment options available at Misericordia. The ophthalmologist will discuss which is the best option for each individual.
One treatment is a thermal laser used to seal damaged blood vessels and prevent them from leaking.
Eyelea, Lucentis and Avastin are drugs that have been shown to slow the progression of wet AMD and in some patients vision may improve. These drugs are injected into the back of the eye by an ophthalmologist in a series of appointments.
Photodynamic therapy is another treatment which involves injecting a light-sensitive dye (called Visudyne) into a vein then shining a laser onto the macula. A reaction between the dye and the light causes the blood vessels to seal preventing further leaking.
People with AMD rarely go completely blind. By using peripheral vision and with vision rehabilitation, individuals are taught how to optimize their remaining vision.