Age-Related Macular Degeneration
What is Age-Related Macular Degeneration?
Age-Related macular degeneration (AMD) is a gradual degeneration of the central vision which affects the ability to see objects clearly and to perform certain tasks. It affects the macula, the central part of the retina. AMD affects approximately 1 million Canadians and is the leading cause of vision loss in the developed world.
- Family history of AMD
- High Blood Pressure
- Long-term exposure to the sun without sun protection
Most cases of AMD start in the “dry” form where there may be an accumulation of pigmentation, thinning of the macular tissues or a combination of both. The loss of vision is usually gradual and usually less severe than Wet AMD. In some cases however, AMD can lead to severe central vision loss.
Approximately 10-15% of people with Dry AMD will progress to Wet AMD. This form is more serious and devastating in terms of vision loss. Wet AMD is when abnormal blood vessels begin to grow under the thinning and pigmented tissues of the macula. These fragile blood vessels can leak leading to drastic changes in vision loss.
With AMD early detection and routine comprehensive eye examinations are the key to early diagnosis. During the eye examination the retina and the macula are examined for any pigmentation which could be early signs of AMD. An Amsler Grid, a checkerboard pattern grid, may be used if there is any central vision distortion.
Digital Retinal Photography helps capture an image of the retina and macula and is useful in determining if the macular pigmentation is changing over the course of visits. An OCT may also be recommended. This is a special scan that produces a 3D cross-sectional view of the retina and macula for better diagnosis.
Treatments are aimed at slowing down the progression of vision loss considerably. If there is a family history, nutritional supplements and polarized sunglasses are generally recommended. Maintaining a healthy diet and active lifestyle in addition to quitting smoking are good measures in protecting the eyes from developing AMD.
Other treatments depend on the stage of the AMD. For Wet AMD, medications such as Avastin, Eyelea, Lucentis and Macugen help stop the development of new blood vessel growth. In some cases Photodynamic Therapy (PDT) can be used to activate a medication called Visudyne which is injected into the arm. This procedure helps destroy the new blood vessel growth and slow down the rate of vision loss.