title: Clinical investigation of the cup/disc ratio.
abstract: 1,277 white and 387 black male veterans were studied in an attempt to determine the racial difference, if any, between the distribution of cup/disc ratios in these two groups of non-glaucomatous patients. The data show a highly significant statistical difference between white and black patients in regard to normal variation of their C/D ratios. Although there were no differences between the prevalence of C/D ratios of 0.3 and less, there were important differences in the prevalence of ratios of 0.5 and greater. Blacks had C/D ratios of 0.5 and greater at almost five times the frequency of whites.
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D044383:Black People; D006801:Humans; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000033:anatomy & histology*; D044465:White People