The prevalence of the eye disease age-related macular degeneration is projected to increase substantially by 2050, but the use of new therapies is expected to help mitigate its effects on vision, according to results of simulation modeling reported in the April issue of Archives of Ophthalmology.
Age-related macular degeneration (AMD) occurs when the macula, the area of the eye's retina responsible for sharp vision, begins to deteriorate. In 2000, as many as 1.75 million Americans reached the advanced, vision-threatening stages of AMD, according to background information in the article. "The prevalence of AMD and its resultant morbidity [illness and disability] is likely to increase as the U.S. population ages because the annual incidence of AMD increases with age from less than 1 percent for those younger than 60 years to greater than 5 percent for people aged 80 years and older," the authors write.
"Newly discovered prophylactic [preventive] and treatment therapies for AMD offer substantial improvements over past therapies and could potentially offset some degree of future AMD morbidity," they continue. Preventive therapies include antioxidant vitamins that could slow the progression of AMD from early to late stages. Treatments for more advanced forms of the disease include laser and photodynamic therapies and anti–vascular endothelial growth factor (anti-VEGF) injections, which can prevent growth of excess blood vessels in the eye and thereby improve vision or prevent further vision loss for up to two years.
To estimate the possible effects these new treatments might have on future disease burden, David B. Rein, Ph.D., of RTI International, Research Triangle Park, N.C., and colleagues simulated cases of AMD and related complications for the years 2010 through 2050. Using existing data to estimate the number of individuals in each stage of the disease based on age, sex and race or ethnicity, they modeled the population's progression over time under five different treatment scenarios. These ranged from no treatment at all to combinations of vitamins to prevent progression of early AMD with laser and anti-VEGF therapies for those at later stages.