Purpose The aim of this study was to investigate the correlation between glaucoma and retinal vein occlusion (RVO) using quantitative metrics of vascular stasis on optical coherence tomography angiography (OCTA). Patients and methods This is a prospective observational, cross-sectional, case–control study that evaluated the retinal peripapillary venous tortuosity index (VTI), as a sign of vascular stasis, by using OCTA images. The study included 45 eyes of 45 patients who were equally distributed among three study groups: healthy controls (15 eyes), glaucomatous eyes with no RVO (15 eyes), and glaucomatous eyes with unilateral RVO (15 eyes). The OCTA scans were also evaluated to obtain the vessel density of the peripapillary and macular capillary plexuses for evidence of capillary nonperfusion. Results There was a statistically significant difference in the VTI among the three groups ( P <0.001). The highest VTI was in the glaucoma with RVO group (1.13±0.02, 1.16±0.02) followed by the glaucoma without RVO group (1.06±0.01, 1.07±0.01) and the healthy control group (1.04±0.01, 1.05±0.01). The vessel density was significantly less ( P =0.002) in the macular superficial capillary plexus in the glaucomatous eyes with RVO (39.8±5.5%), and in the eyes without RVO (40.1±4.3%) compared to the nonglaucomatous eyes (47.6±3.2%). On the other hand, the deep capillary plexus showed no statistically significant differences between the three groups. Conclusions Primary glaucomas contributed to higher peripapillary vascular stasis, manifested by increased venous tortuosity, associated with the precipitation of RVO. Larger longitudinal studies may be required to evaluate the peripapillary VTI as a prognostic marker for developing RVO in glaucoma.
Guirguis et al. (Thu,) studied this question.