Treatments for Wet AMD
Presently, three treatments for wet AMD have been scientifically proven in large clinical trials and are approved in Canada.
Laser photocoagulation - This procedure uses a thermal (heat) laser to destroy the fragile, leaky blood vessels caused by AMD, preventing further loss of vision. Since the blood vessels are beneath the retina, the laser has to pass through the retina to reach them, resulting in damage to the retina as well (usually resulting in a permanent blind spot in the vision).
Laser is therefore more effective for leaky blood vessels that have developed away from the central part of the macula, known as the fovea. The risk of new blood vessels developing after this treatment is high, and repeated treatments may be necessary. Since the development of photodynamic therapy, laser photocoagulation treatment is rarely used.
Photodynamic therapy - This procedure was developed so that the laser can go through the retina with little or no damage. It includes the use of a light-activated drug called verteporfin, which is injected intravenously, travels through the body to the eye and accumulates in the area of new blood vessel growth. Low-energy light in a cool laser beam is then applied to these vessels, activating the drug, which then destroys or slows the leaky blood vessels. Photodynamic therapy slows the rate of vision decline, and in some cases it may stabilize vision.
Anti-Angiogenesis or anti-VEGF therapy - Angiogenesis means the increased or abnormal growth of blood vessels, associated with numerous diseases including AMD. Certain proteins, such as vascular endothelial growth factor (VEGF), have been shown to play an important part in abnormal blood vessel growth and blood vessel leakage, two of the primary problems with wet AMD.
When the abnormal vessels leak blood or other fluid, they cause blurring in the central vision and damage to the light-sensitive photoreceptor cells. Anti-angiogenesis aims at stopping blood vessel growth before it damages the retina by blocking the VEGF protein, so it is also called 'anti- VEGF.'
The first approved anti-VEGF treatment in Canada (pegaptanib) helps slow the progression of the disease and preserve vision.
Pegaptanib sodium injection - This treatment is delivered by intravitreous injection (an injection into the central cavity of the eye) every six weeks. The drug has been approved by Health Canada for the treatment of wet AMD. The treatment inhibits a key signal that causes blood vessels to grow and leak which in turn slows the damage done to an individual's sight.
Ranibizumab - This treatment, delivered by injection to the eye every four to six weeks, has gone through extensive clinical trials. Ranibizumab has been shown to actually reverse vision loss for 40% of wet AMD patients – it is the first clinically proven treatment to do so, so it offers great hope for many people with wet AMD. Ranibizumab also prevents further vision loss in 95% of patients. It is approved for use in Canada, the United States, the United Kingdom, France, Australia, Switzerland and other countries around the world.
Wet AMD Treatment Coverage: Latest Developments in Canada (2009)
Fantastic news for people in British Columbia, Saskatchewan, Newfoundland and Labrador, and the Yukon who are living with wet AMD: your governments have recently decided to add the wet AMD treatment Lucentis to your health coverage, joining Ontario and Quebec in reimbursing this sight-saving medication. Read more about the latest development in wet AMD treatment in Canada
For more information about current treatments for wet AMD, visit the AMD Alliance International website.