Age-Related Optic Nerve Head and Retinal Microvasculature Dropout Varies by Race

Abstract

Purpose : To examine age-related differences in the pattern and distribution of microvasculature density and retinal tissue thickness in healthy eyes of individuals of African descent (AD) and European descent (ED).

Methods : OptoVue Avanti (optical coherence tomography angiography (OCTA) imaging) macula (3 x 3 mm²) and optic nerve head (ONH, 4.5 x 4.5 mm²) scans of 20 eyes of 12 individuals of AD and 77 eyes of individuals of 41 ED from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES) were included. Racial differences in whole image macula vessel density of the superficial and deep layer plexuses, whole image ONH capillary densities (CD after removal of the large vessels), global ganglion cell complex (GCC, excluding the fovea) and global circumpapillary retinal nerve fiber layer (cpRNFL) thickness of each eye were assessed using non-parametric clustered Wilcoxon signed-rank tests.

Results : Mean age was similar between AD and ED individuals [mean (95% CI: 58.9 (52.3, 62.3) and 58.9 (53.1, 64.8) years, respectively]. No significant racial differences were observed between any of the baseline vessel density or tissue thickness parameters investigated (all p ≥ 0.07). However, the age-related decrease of superficial layer macular vessel density, ONH vessel density, GCC thickness, and cpRNFL thickness per year was greater in individuals of AD compared to ED (all p≤0.050). Specifically, we found significant racial differences in age-related changes for superficial layer macular vessel density (AD: -0.25% and ED: 0.07% per year) and peripapillary capillary density (AD: -0.19% and ED: -0.02%) per year). Racial differences in age-related decrease in GCC (AD: -0.91µm and ED: -0.29 µm per year) and cpRNFL thickness (AD: -1.22µm and ED:-0.31 µm per year). Deep layer macula vessel density did not show significant racial difference in age-related changes.

Conclusions : Age-related decrease in superficial macular vessel density, ONH vessel density, cpRNFL, and GCC were greater in individuals of AD compared to ED. Further work is needed to determine whether these racial differences in age-related changes influence the higher the prevalence and incidence of glaucoma in individuals of AD. These data can also inform reference databases of vessel density measurements with respect to race.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.