Relationship Between Macular Vessel Density and Total Retinal Blood Flow in Primary Open-angle Glaucoma.

PRCIS An association between macular vessel density and total retinal blood flow was demonstrated in subjects with primary open-angle glaucoma and visual field loss. PURPOSE To report relationships of macular vessel density metrics and total retinal blood flow in primary open-angle glaucoma (POAG). MATERIALS AND METHODS A total of 24 POAG and 19 healthy control subjects participated in the study. Subjects underwent optical coherence tomography and angiography (OCT/OCTA) for measurements of inner retinal thickness (IRT), vessel density (VD), and spacing between large and small vessels (SLV, SSV). Doppler OCT imaging was performed for total retinal blood flow (TRBF) measurement. In POAG subjects, automated perimetry was performed and visual field (VF) loss expressed as mean deviation was measured. RESULTS Compared to the control group, POAG group had decreased VD, TRBF, IRT, and increased SLV (P<0.0001). Decreased VD (Pearson correlation, r=0.51; P<0.0001; N=43) and increased SLV (Spearman correlation, rs=-0.47; P=0.001) were correlated with decreased TRBF. Decreased VD and SSV (r≥0.39; P≤0.001; N=43) and increased SLV (rs=-0.71; P<0.0001) were associated with decreased IRT. Decreased VF MD was correlated with decreased VD, SSV, IRT (r≥0.53; P≤0.001; N=24), and with increased SLV (rs=-0.84; P<0.0001). CONCLUSION The finding of an association between macular vessel density and total retinal blood flow supports the role of vascular factors in the pathophysiology of POAG and potential conduct of future studies aimed at identifying multiple image-based vascular metrics for disease diagnosis.