Retinal nerve fiber layer measurements in normal black subjects as determined with scanning laser polarimetry

PURPOSE: This study aimed to obtain normal nerve fiber layer (NFL) measurements by means of scanning laser polarimetry in black subjects and to compare these measurements with those in normal white subjects.

METHODS: Polarimetric NFL measurements were obtained in 1 eye of 133 normal black subjects and 133 age- and gender-matched white subjects. Ratios were determined for the superior and inferior NFL, each relative to the nasal value (S/N and I/N, respectively). Results of black and white subjects were compared by means of the Student's t test. The effect of age on NFL measurements was determined with linear regression analysis.

RESULTS: The mean S/N was statistically significantly lower in black subjects (1.7) when compared with that of white subjects (2.5). Similar values were obtained for I/N. In this cross-sectionally performed study, a negative, albeit not significant relation (-0.003) was recognized between NFL measurements and age for both S/N and I/N in black subjects. In the white subjects, there was a statistically significant relation of -0.012 between age and NFL measurements.

CONCLUSIONS: The NFL retardation is less in black than in white subjects. Compared with white subjects, the decrease in NFL measurements of black subjects over time, cross sectionally, appears less.