CHOROIDAL THICKNESS IN RELATION TO ETHNICITY MEASURED USING ENHANCED DEPTH IMAGING OPTICAL COHERENCE TOMOGRAPHY.

Abstract

To investigate the posterior choroidal thickness in healthy subjects of three different ethnicities. In this prospective cross-sectional study, the choroidal thickness of 88 individuals (176 eyes) was measured using enhanced depth imaging-spectral domain optical coherence tomography. Subfoveal choroidal thickness was measured between the retinal pigment epithelium-Bruch membrane complex and chorioscleral interface. Nasal, temporal, superior, and inferior choroidal thicknesses at 0.5, 1.5, and 3.0 mm locations from the fovea were evaluated as well. Males and females were perfectly matched by number in all groups. The mean age of the entire study population was 27.43 ± 1 years. Mean subfoveal choroidal thicknesses of whites, Africans, Asians, and entire study population were 403.62 ± 37.4 μm, 372.47 ± 31.4 μm, 383.64 ± 40 μm, 386.64 ± 10.5 μm, respectively. Mean spherical error of the entire study population was -1.2685 diopter. Whites had the longest eyes on average 24.17 mm > 24.08 mm (Africans) > 23.86 mm (Asians), with the statistical mean of 24.04 mm for the entire study population. Subfoveal choroidal thickness was not significantly correlated with ethnicity in either ethnic group (P > 0.05). Subfoveal choroid thinned by 2.51 μm per 1 year increase in age (P = 0.282). Subfoveal choroidal thickness and sex were not significantly correlated to (P = 0.402). Subfoveal choroidal thickness was in strong negative correlation only with refractive error (P = 0.01) and axial length (P = 0.008). The intereye difference in subfoveal choroidal thickness was not statistically significant (P = 0.845). Enhanced depth imaging-spectral domain optical coherence tomography is a productive imaging method to study the choroidal thickness. Subfoveal choroidal thickness is not significantly correlated with ethnicity. The study reproduced previously found relations between thinner choroids and longer axial lengths, and increasing myopic refraction and showed no significant associations between subfoveal choroidal thickness and age and sex. Either the right or left eye can be used in future studies.