Relationship Between Foveal Threshold and Macular Structure/Function/Vessel Density in Glaucoma

Purpose: To investigate the hypothesis that macular structure, function, and vessel density (VD) measurements can predict foveal threshold (FT) outcomes in glaucomatous eyes. Materials and Methods: One hundred ninety-five eyes from 195 subjects (134 subjects with early-to-moderate stage open-angle glaucoma and 61 healthy controls) who underwent optical coherence tomography angiography imaging and 24-2 visual field (VF) testing with FT measurements on the same day were retrospectively enrolled in this study. The association of FT with macular structural/functional/VD measurements was evaluated using partial correlation analyses with adjustment for age and linear regression analyses. Results: FT showed significant correlations between the thickness of the macular ganglion cell-inner plexiform layer (mGCIPL) (r=0.330, P<0.001) and the mean sensitivity (MS) of the central 5 and 10 degrees VF points (r=0.448, Pr=0.361, P<0.001). Significant correlations were also found between FT and VD measurements at the inferior and superior parafoveal sectors (r=0.455, Pr=0.438, P<0.001). In multivariate linear regression analyses controlling the covariates, the thickness of the mGCIPL, central 5 degrees VF MS, and parafoveal VD were significantly associated with FT (all P<0.001). There was also a significant association between FT and logMAR best-corrected visual acuity (beta=-5.647, P<0.001). Conclusions: Macular VD along with mGCIPL thickness and central 5 degrees VF MS independently predict FT outcomes even in the eyes of patients with early-to-moderate stage open-angle glaucoma.