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

Precis: An association between macular vessel density (VD) and total retinal blood flow (TRBF) was demonstrated in subjects with primary open-angle glaucoma (POAG) and visual field (VF) loss. Purpose: The purpose of this study was to report relationships of macular VD metrics and TRBF in 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 for measurements of inner retinal thickness (IRT), VD, and spacing between large vessels (SLV) and small vessels (SSV). Doppler optical coherence tomography imaging was performed for TRBF measurement. In POAG subjects, automated perimetry was performed and VF loss expressed as mean deviation was measured. Results: Compared with 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, r (s)=-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 (r (s)=-0.71; P<0.0001) were associated with decreased IRT. Decreased VF mean deviation was correlated with decreased VD, SSV, IRT (r >= 0.53; P <= 0.001; N=24), and with increased SLV (r (s)=-0.84; P<0.0001). Conclusions: The finding of an association between macular VD and TRBF 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.