Peripapillary and Macular Microcirculation in Glaucoma Patients of African and European Descent Using Optical Coherence Tomography Angiography

Précis: We found no significant differences in peripapillary and macula microcirculation blood flow metrics in eyes with open-angle glaucoma of African descent (AD) and European descent (ED) as detected by optical coherence tomography angiography (OCTA). Purpose: The purpose of this study was to investigate the peripapillary retinal nerve fiber layer (RNFL) and macular vascular microcirculation in subjects of AD and ED with open-angle glaucoma using OCTA. Patients and Methods: One eye from each subject was scanned using AngioPlex OCTA system covering both a 6×6 mm scanning area centered at the optic nerve head and at the foveola. Peripapillary RNFL and macular microcirculation were measured by calculating the overall flux and vessel area density excluding the large retinal vessels. Two-sample, independent t tests were used to compare the OCTA metrics between AD and ED eyes. Linear regression models were used to investigate the correlation between OCTA metrics and structural and functional parameters. Results: Twenty-eight eyes of AD and 56 eyes of ED were included in the study. There was no significant difference in age, sex, hypertension, antihypertensive medications, diabetes, systolic and diastolic blood pressure, mean ocular perfusion pressure, RNFL thickness and visual field (VF) mean deviation and VF pattern standard deviation (P≥0.054) between AD and ED eyes included. Both groups had similar OCTA blood flow metrics (P≥0.161). OCTA blood flow metrics were significantly correlated with VF mean deviation (r≥0.466), VF pattern standard deviation (r≤−0.366) and RNFL thickness (r≥0.333). Conclusions: No significant differences were found in peripapillary and macular microcirculation detected by OCTA between AD and ED glaucomatous eyes. Peripapillary and macular microcirculation were significantly correlated with disease severity in AD and ED glaucomatous eyes.