Analysis of normal retinal nerve fiber layer thickness by age and sex using spectral domain tomography

Background: To analyze the nerve fiber layer thickness in a heterogeneous Indian population according to age and sex and to compare this parameter to published normative data on the Caucasian population to better understand the racial differences. Materials and Methods: A total of 400 patients of both gender belonging to various age groups were evaluated using Cirrus HD optical coherence tomography (OCT), Carl Zeiss, Meditec, Dublin. The results were evaluated and compared to determine the normal retinal nerve fiber layer thickness (RNFLT) and its variations with age and sex. Results: Average nerve fiber thickness along the 3.4 mm diameter circle around the optic nerve head was approximately 90.57 ± 11.59 μm. There was no significant difference seen between males and females for mean, quadrant, and clockwise RNFLT. This was the same in all the subgroups of our study. Conclusions: Our results provide the variations of RNFL in Indian population. To the best of our knowledge, this is the first study in our country done with a high sample size in the Cirrus HD-OCT machine