Diurnal fluctuations of macular vessel density in patients with primary open-angle glaucoma and healthy subjects.

Abstract

To investigate the diurnal fluctuations of macular vessel density (VD) in primary open-angle glaucoma (POAG) and healthy subjects using optical coherence tomography angiography. A total of 22 POAG eyes and 15 healthy eyes were included in this study. Macular VD, intraocular pressure, and blood pressure were repeatedly measured from 8 AM to 8 PM at a 2-h interval on a single day. the macular VD measurements, their diurnal fluctuations, including the difference between their maximal and minimal value (max-min) and their coefficient of variation (CV) in superficial capillary plexus (SCP) and deep capillary plexus (DCP). The mixed-effects model was performed to compare the fluctuations between groups. After adjusted age, the diurnal fluctuations of macular VD in SCP and DCP were significantly higher in POAG eyes compared with healthy subjects (max-min: 6.65 ± 3.54%, 3.92 ± 3.63%, respectively; p = 0.037 and CV: 0.06 ± 0.03, 0.04 ± 0.03, respectively; p = 0.003). The fovea VD in DCP of POAG eyes was higher than in healthy subjects (31.52 ± 4.68% and 25.71 ± 3.70%, p = 0.009). However, there was no significant difference between the fovea VD in SCP in two groups (20.97 ± 4.75% and 19.29 ± 4.35%, p = 0.670). The diurnal macular superficial VD measured in most of the participants was lower in the morning. Whether it is a max-min or a CV assessment method, the POAG eyes had more significant diurnal fluctuations of macular VD than healthy controls, suggesting impaired vascular autoregulation in POAG eyes.