Comparison of Retinal Vessel Diameter Between Open-Angle Glaucoma Patients With Initial Parafoveal Scotoma and Peripheral Nasal Step

Purpose To compare retinal vessel diameters (RVDs) between open-angle glaucoma (OAG) patients with initial parafoveal scotoma (PFS) and those with initial peripheral nasal step (PNS). Design Retrospective, cross-sectional study. Methods We enrolled 151 eyes of 151 patients with OAG (83 with normal-tension glaucoma [NTG] and 68 with primary open-angle glaucoma [POAG]). The patients were categorized into the PFS and PNS groups according to the location of the initial visual field (VF) defect. Clinical characteristics and RVD indices—central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE)—were compared between the groups. Subgroup analyses were conducted in the NTG and POAG groups. Results Forty-six patients had PFS and 105 had PNS. The CRAE of the PFS group was significantly lower than that of the PNS group in all glaucoma patients (P = .001). However, neither the mean deviation in VF nor that in the average retinal nerve fiber layer thickness showed significant intergroup differences. In the NTG subgroup analysis, the CRAE of the PFS group was significantly lower than that of the PNS group (P = .013). Conversely, in the POAG subgroup analysis, the CRAE in the PFS group did not differ significantly from that in the PNS group (P = .123). Conclusions Retinal arteriolar diameter was narrower in OAG patients with initial PFS than in those with initial PNS, especially in the NTG group. This suggests that the initial location of the VF defect may be associated with the vascular mechanism in patients with glaucoma.