Background: Few studies have characterized ethnic variations in standard ophthalmic measures. We tested the hypothesis that nerve fiber layer thickness would show characteristic differences between white and black individuals. We also examined whether ophthalmic measures would show intraethnic differences.
Methods: Seventy participants (mean age: 68.27+/- 5.97 years; blacks: 59% and whites: 41%) were recruited from Brooklyn communities. Sociodemographic and medical data were obtained, and eligible volunteers underwent eye examinations at SUNY Downstate Medical Center.
Results: ANCOVA showed that blacks were characterized by significantly worse visual acuity (F=4.14, p=0.05), larger horizontal and vertical cup-to-disk ratios (F=4.53, p=0.04; F=6.08, p=0.02, respectively), and thinner nerve fiber layer than their white counterparts (F=22.61, p=0.009). Within the black ethnicity itself, Caribbean Americans showed significantly thinner nerve fiber layer than did African Americans (F=7.52, p=0.01).
Conclusion: Findings are consistent with previous reports of racial/ethnic differences in ophthalmic measures. Moreover, they suggest that black ethnicity may not be homogeneous regarding ophthalmic variables, particularly when examining nerve fiber layer thickness. Studies investigating ethnic differences in eye diseases should examine intragroup factors that could influence interpretation of clinical data.