Normal macular structure measured with optical coherence tomography across ethnicity.

Abstract

The difference in prevalence of various retinal pathologies in people of different ethnicity is well established. Optical coherence tomography (OCT) is a widely used technique that allows quantitative analysis of macular structure. In this study, we investigated macular layer morphology in healthy subjects using high-resolution spectral domain (SD) OCT across ethnicities comparing Asian (ie, Indian subcontinent) and Caucasian individuals. 133 healthy volunteers (67-Asian, 66-Caucasian) were examined using SD-OCT. Average retinal and nerve fibre layer thickness were measured in a semiautomated way. Analysis of the measurements of each retinal layer at the macula was quantified using tomograms obtained by SD-OCT. In this study, we find significant difference in macular structure in Asian and Caucasian participants. Caucasian subjects have thicker inner segment (p=0.015 in the central region), outer segment (p=0.04 in the temporal region) and outer nuclear (p=0.021 and p=0.03 for the central and temporal regions, respectively) layers, while Asians demonstrate thicker retinal pigment epithelial layer (p=0.004 for the temporal region). Differences in macular morphology due to ethnicity should be considered in determining control values for diagnostic purposes, and can be used to guide future studies in risk and prognosis for macular pathologies.