Peripapillary and Macular Vascular Density in Patients With Preperimetric and Early Primary Open Angle Glaucoma

Decreased circumpapillary vascular density (cpVD) and average retinal nerve fiber layer (RNFL) thickness were detected at different locations in eyes with preperimetric glaucoma (PPG). Although RNFL loss was more prominent in preperimetric eyes, in early glaucoma, both cpVD and RNFL thickness showed comparable diagnostic ability.

To evaluate changes in circumpapillary and macular vascular density and investigate correlations between vascular and structural parameters in PPG and early glaucoma.

This cross-sectional study included a total of 27 patients with PPG in 1 eye and early primary open angle glaucoma in the fellow eye, as well as a control group consisting of 27 eyes of 27 healthy volunteers. All subjects underwent optical coherence tomography angiography (OCTA) imaging. RNFL and macular ganglion cell complex measurements were obtained simultaneously with vascular parameters by AngioVue OCTA using the single-scan protocol. cpVD was examined in 8 sectors. Diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve.

In preperimetric eyes, average RNFL thickness and whole-image vessel density had comparable diagnostic performance (area under the receiver operating characteristic curve =0.853 and 0.753, respectively). Compared with the control group, PPG eyes had significantly lower RNFL thickness in all quadrants (P<0.001-0.003) except for the temporal quadrant, whereas cpVD differed only in the nasal inferior and nasal superior sectors (P=0.001 and 0.041, respectively). In early glaucoma eyes, cpVD differed significantly from controls in all sectors except for the inferotemporal, temporal inferior, and temporal superior sectors, whereas perifoveal macular vascular parameters differed in all quadrants (all P<0.05). cpVD was strongly correlated with RNFL thickness in the superior, nasal, and temporal quadrants (r=0.664, 0.698, and 0.649, respectively, P<0.001) and moderately correlated in the inferior quadrant (r=0.450, P<0.001).

Although RNFL involvement is valuable in the diagnosis and follow-up of PPG, the change in nasal cpVD has an important place in these patients. The role of macular vascular parameters and macular ganglion cell complex in glaucoma follow-up becomes important in early glaucoma. Longitudinal studies are needed to determine the place of OCTA in the diagnosis and follow-up of glaucoma.