Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in Americans older than 50, affecting more than two million people.
The American Academy of Ophthalmology wants to remind people that although AMD is incurable, there are new treatments that can usually recover lost vision and prevent further vision loss from the disease.
The Academy encourages those older than 50 to see an ophthalmologist for a comprehensive, dilated eye examination every one to two years to ensure that AMD and other vision-threatening conditions are detected and treated early.
"The key in treating AMD is catching it early; early detection is the best defense against losing your vision," said Academy clinical correspondent Lylas G. Mogk, MD, chair of the Academy's Vision Rehabilitation Committee. "Research continues, and I think we'll see increasingly effective AMD treatments becoming available in the near future."
What is AMD?
AMD, progressive and usually painless, affects the macula, a small, specialized area of the retina, located at the back of the eye and responsible for central vision. AMD causes central vision to blur, but leaves peripheral vision intact.
There are two types of AMD: dry and wet. Approximately 90 percent of people with AMD have the dry form, in which aging changes in the macula results in gradual vision loss.
Although only 10 percent of people with AMD have the wet form, it generally progresses much quicker than the dry form. Wet AMD is characterized by the growth of abnormal retinal blood vessels that leak blood or fluid, causing rapid and severe central vision loss.
Reducing AMD Risk
"The most important risk factors for AMD include smoking, high blood pressure and diet," said Dr. Mogk. " Recommendations for reducing the risk of developing AMD include not smoking; eating a heart-healthy diet rich in fish, fruit and green leafy vegetables; avoiding foods with trans fats; exercising and controlling your blood pressure and weight."
Other risk reducers include:
The National Eye Institute's (NEI) Age-Related Eye Disease Study found that high levels of antioxidants and zinc can reduce the risk of vision loss by about 25 percent in patients with "intermediate" AMD in one or both eyes and those with "advanced" AMD in only one eye. (Smokers and ex-smokers should not use beta carotene because studies have shown an association with lung cancer and beta carotene in smokers.) A new study will evaluate the effects of lutein and omega-3 fatty acids.
Anti-Vascular Endothelial Growth Factor (VEGF) drugs inhibit the development of unwanted blood vessels that cause wet AMD, and these agents help prevent further visual loss and even improve vision. At the current time, these are injected directly into the eye. Two drugs have already been approved by the FDA, Macugen and Lucentis, and the makers of several others are looking to gain FDA approval.
Conventional laser therapy and photodynamic therapy are also treatments for wet AMD and have been approved by the FDA based on studies by the National Eye Institute (NEI).