Abstract
Abstract: :
Purpose: Age–related macular degeneration (AMD) is the leading cause of irreversible vision loss in the United States in people age 65 and older. Given the significance of the disease, the identification of risk factors for AMD may prove useful for prognosis and treatment of these patients. Recently, it has been shown that monocyte chemotactic protein (MCP)–1 or C–C chemokine receptor (CCR) 2 deficient mice develop clinical features of AMD, including drusen and choroidal neovascularization. Similarly, in humans the valine to isoleucine substitution at position 64 is a common polymorphism in the human CCR2 gene and has been associated with several diseases. The purpose of this study is to determine the incidence of the Val64Ile polymorphism of the CCR2 gene in patients with advanced AMD. Methods: Patients at a university–based practice between the ages of 55 and 80 underwent dilated funduscopic exam, accompanied by fundus photography. Fifty patients were determined to have neovascular AMD, confirmed angiographically. Fifty age and race matched patients were selected as the control group. Whole blood from patients and controls was sampled. Allele–specific amplification primers for CCR2–Ile64 polymorphism were used, and two polymerase chain reactions (PCR) were performed on each DNA sample. Results: PCR results showed a 25% incidence of the Val64Ile genetic polymorphism in the patients with AMD, while the incidence in the age and race–matched population was only 10%. This difference was shown to be statistically significant. Conclusions: The increased incidence of the Val64Ile genetic polymorphism of the CCR2 gene in patients with advanced AMD may have important implications in screening patients who may be at increased risk for advanced AMD and severe vision loss.
Keywords: age–related macular degeneration • genetics • choroid: neovascularization