April 14 (HealthDay News) -- Although the rate of age-related macular degeneration is on the increase, newer treatments could help reduce the most serious effects of the disease by about 35 percent, new estimates suggest.
In a study funded by the U.S. Centers for Disease Control and Prevention, researchers report that as many as 9.1 million people will have age-related macular degeneration (AMD) in 2010, but that 17.8 million people will have the potentially blinding eye disease by 2050.
"What we found is that due to aging, the number of cases of early and advanced AMD will increase dramatically no matter what," said study author David Rein, a senior research economist from RTI International in Research Triangle Park, N.C. "In 2050, we project there will be 1.57 million cases of blindness [caused by AMD] with no treatment. But, with vigorous treatment, that number's just about 1 million."
Results of the study are published in the April issue of the Archives of Ophthalmology.
Age-related macular degeneration is a serious eye disease that causes the breakdown of the macula, which is located in the retina. The macula gives you clear central vision, which is essential for reading and driving, even for just seeing people's faces. AMD is a leading cause of vision loss in people over 65, according to the American Academy of Ophthalmologists (AAO).
Risk factors for AMD include advancing age, a family history of the disease, high blood pressure, smoking and obesity, according to the AAO. Though there are treatments that help some people, there is no cure for AMD.
Most of the treatments for AMD are relatively new, only widely available since about 2001, according to Rein. The easiest and cheapest intervention is a special vitamin/mineral combination (vitamins C, E, beta carotene, zinc and copper) that may slow the progression of AMD. This treatment only costs about $100 per year, and when used early in the disease can "reduce vision-threatening disease by 25 percent," Rein noted.
Other possible treatments include anti-vascular endothelial growth factor (anti-VEGF), which slows the growth of leaking blood vessels in the eyes, laser therapy or photodynamic therapy (PDT), which combines the use of medication and laser therapy to reduce blood vessel leakage in the eyes.
Using a statistical model, the researchers estimated that the rate of visual impairment would drop by 2.4 percent if everyone with AMD were treated with PDT alone, but by 22 percent if PDT was combined with vitamin treatments. If, in the future, everyone were treated with laser therapy and anti-VEGF, visual impairment and blindness from AMD would decrease by 16.9 percent, and the final scenario -- early vitamin treatment and laser therapy -- would reduce serious visual problems in AMD by 34.5 percent.
"Age-related macular degeneration is a major public health problem, and as people are living longer, more people are going to develop some form of macular degeneration," said Dr. Alexander Aizman, a clinical instructor in the department of ophthalmology at New York University School of Medicine in New York City. "The scenarios in this study are very plausible."
Aizman said that although there's currently no specific preventive treatment to avoid AMD altogether, the same things that keep your heart and the rest of your body healthy -- maintaining the proper weight, exercising, not smoking and avoiding secondhand smoke -- can also help keep your eyes healthy.
"If you have a relative who has been diagnosed with AMD, it's important to know that you're probably at a higher risk of AMD than the general population," said Aizman. "If you're 60 or older, have regular eye checkups with an ophthalmologist or a retinal specialist to find out if you have any early changes that suggest AMD."
SOURCES: David Rein, Ph.D., senior research economist, RTI International, Research Triangle Park, N.C.; Alexander Aizman, M.D., clinical instructor, department of ophthalmology, New York University School of Medicine, New York City; April 2009, Archives of Ophthalmology