To evaluate racial differences in optic nerve head peripapillary capillary density measured by optical coherence tomography angiography (OCTA) in patients with open-angle glaucoma.
Observational, cross-sectional study.
A total of 284 eyes of 195 glaucoma patients and 108 eyes of 58 healthy subjects from the Diagnostic Innovations in Glaucoma Study.
Global and sectoral circumpapillary capillary density (cpCD) loss in European-descent (ED) and African-descent (AD) participants were compared. Areas under the receiver operating characteristic curves (AUROC) were used to evaluate diagnostic accuracy of cpCD and global circumpapillary retinal nerve fiber layer thickness (cpRNFL) in the two groups after adjusting for confounders.
Peripapillary capillary density and cpRNFL measurements and their estimated loss RESULTS: AD and ED subjects with glaucoma had similar age and glaucoma severity. After adjusting for age, disc area and other confounders, significantly lower cpCD was found in ED eyes compared to AD in mild glaucoma (mean(95% CI) 42.2 (41.2, 43.2) and 46.5 (44.8,48.1)%, respectively; adjusted difference= 4.4 (2.6, 6.2); p<0.001) and moderate to advanced glaucoma (34.7 (33.0, 36.3) and 38.5 (35.1,41.8)%, respectively, adjusted difference= 4.8 (1.6, 8.1); p=0.005). Although capillary density loss was greater in all sectors in ED compared to AD subjects, a similar sectoral pattern of density loss was observed in both racial groups. Lower MD and older age were associated with lower cpCD in both races in multivariable models. The adjusted AUROC for discriminating between healthy and glaucomatous eyes for cpCD was higher for ED (0.95) compared to AD patients (0.68) (p<0.001). Sensitivity (95% CI) at 95% specificity in AD subjects was lower than ED subjects for cpCD (0.32 (0.11, 0.64) vs 0.83 (0.69, 0.93); respectively; p<0.001). CpRNFL had lower discriminating ability for detecting glaucoma in AD (0.79) compared to ED subjects (0.93). (P=0.195) CONCLUSION: Although peripapillary capillary density parameters had good diagnostic accuracy for detecting glaucoma in ED patients, their diagnostic accuracy only was modest in AD patients. Diagnostic performance of cpCD is race-dependent and clinicians should be aware that it has poorer performance in AD patients.

Copyright © 2020. Published by Elsevier Inc.