Macular Degeneration Screening
Macular degeneration is a condition that can cause permanent loss of detailed vision. Though it almost never causes total blindness, it is the major cause of loss of vision in people over the age of 50 in our country. Macular degeneration usually starts with the appearance of yellow-colored spots in the macula called drusen. There are two main forms of macular degeneration, a dry form with drusen and atrophy of the retina, and a wet form.
For the dry type of macular degeneration, high dose vitamin and antioxidant therapy has been shown to significantly decrease the long-term risk of vision loss with dry age-related macular degeneration (AMD). The Age-Related Eye Disease Study 2 (AREDS2) is a National Institute of Health trial that has showed the following supplementations can significantly decrease the risk of vision loss even beyond the original supplementation recommendations made by the original AREDS study results in 2001. The supplement ingredients recommended by AREDS 2 are:
Vitamin C 500 mg per day
Vitamin E 400 IU per day
Zinc 25 mg per day
Copper 2 mg per day
*Lutein 10 mg per day
*Zeaxanthine 2 mg per day
omega - 3LCPUFAs
There are a number of over the counter supplements available. Some of these supplements are not based on the AREDS2 recommendations and because these supplements have different, untested combinations of ingredients these should be avoided. AREDS2 based supplements should be taken only if your doctor has diagnosed you with the dry form of age related macular degeneration. There is no proof that any one brand is superior to another nor does Florida Retina Specialists PA, have any financial interest in any of the supplement products.
Smoking is a very important and avoidable risk factor for developing macular degeneration. Also increasing evidence is showing lifestyle changes such as obesity reduction, and blood pressure control may help reduce the risk of vision loss from AMD. Cataract surgery has not been linked to the progression of AMD, and there is also no strong evidence linking UV light to the progression of AMD.
In the wet type of AMD, which occurs in 10% of people, abnormal blood vessels grow under and lift up the retina which results in swelling and bleeding within the retina, causing loss of vision. These abnormal vessels are called choroidal neovascularization. The longer the neovascular membrane continues to leak, bleed and grow, the more central vision will be lost. Signs and symptoms of the wet type of AMD include sudden onset of decreased vision, central distortion, or a central blind spot in vision. An Amsler Grid self-testing by patients is highly effective for detecting early wet macular degeneration. (Someone with wet macular degeneration may view the lines to be distorted or possibly a central dark spot may be present.)
Amsler Grid Appearance with Macular Degeneration.
How one's vision appears with central loss
of vision from
The current best available treatment for wet AMD is an injection of medication into the eye. The medications currently used are Avastin, Lucentis, and Eylea. Studies have shown all three drugs stop the choriodal neovascular membrane from growing and prevent swelling in the retina. There is up to a 40% chance of improving the vision in a patient who has lost vision by giving these medications. Often these medications must be given every 4 to 6 weeks for an extended period of time. Many studies have shown that once the medications are stopped, the vision loss will continue. The National Eye Institute of Health evaluated Lucentis vs. Avastin in a study called the Comparison of Age-related Macular Degeneration Treatment Trials (CATT). The 2 year results were published in summer of 2012 in journal of Ophthalmology which showed Avastin is equivalent to Lucentis in the treatment of wet AMD through two years when using similar dosing regimens. The study also showed that regularly scheduled monthly dosing produced more vision gain than as-needed regimen of treatment for both drugs. Currently, injections of these medications into the eye must be continued at regular intervals to prevent patients from losing vision.