The Role of Ethnicity on the Retinal Nerve Fiber Layer and Optic Disc Area Measured With Fourier Domain Optical Coherence Tomography

Abstract

Purpose: : To determine if there are ethnic differences in RNFL thickness and optic disc area in healthy eyes.

Methods: : 861 healthy eyes from 15 clinics around the world were enrolled. All participants underwent a full eye examination, standard achromatic perimetry (SITA- standard 24-2) and scanning with the RTVue, a Fourier-domain optical coherence tomography (FD-OCT) device manufactured by Optovue, Inc., Fremont CA. All participants had normal visual fields (GHT within normal limits and PSD > 5%) and intraocular pressure < 22 mm Hg. A general linear model using ethnicity, age, and optic disc area was used to determine possible RNFL differences.

Results: : Descriptive statistics for the variables (mean +/- standard deviation) are shown in the table below for the various ethnic groups. Significant ethnic differences were found for average RNFL thickness, taking into account effects of age and optic disc size (P<0.001). Significant ethnic differences were also found for optic disc area (p< .001). No significant differences were found for the correlation of RNFL thickness and age between ethnic groups (similar slopes), or for the correlation of RNFL thickness and optic disc are between ethnic groups (similar slopes).

Conclusions: : Significant effects for ethnicity on RNFL thickness were found, even taking into account age and optic disc size. This finding suggests ethnic specific normative databases may improve clinical efficacy of Fourier Domain OCT.

Keywords: imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • optic nerve