White individuals older than 65 are more likely than black individuals to have characteristics that indicate they will develop more advanced forms of the eye disease age-related macular degeneration (AMD), according to a report.
AMD is a leading cause of vision loss in the United States. Early symptoms include the appearance of drusen (large yellow or white spots in the retina), according to background information in the article. Previous studies have shown a potential difference in rates of AMD between black and white individuals.
Susan B. Bressler, M.D., of the Johns Hopkins University School of Medicine, Baltimore, and colleagues analyzed the eyes of 2,520 individuals (average age 73.5 years) of whom 1,854 were white and 666 were black. Photographs of each eye were taken and assessed for several characteristics of AMD, including drusen and abnormal blood vessel growth.
Larger drusen, connected drusen, those covering a larger area and those closer to the center of the eye were more likely to be found in whites. White individuals were also more likely to already have advanced AMD (1.7 percent vs. 1.1 percent of blacks) and geographic atrophy, another form of AMD, (1.8 percent of whites vs. 0.3 percent of blacks).
"Such data strongly suggest that white individuals are more likely to progress to advanced vision-disabling AMD (certainly to geographic atrophy) than black individuals," the authors conclude. The data also suggest that black individuals may have a mechanism for protection against AMD and other eye abnormalities. "The absence of racial differences in these early lesions in the pericentral (surrounding the center) area suggest that further research is warranted on factors that protect black individuals from lesions in the central zone or promote central lesions in white individuals."