Evaluation of glaucomatous macular and optic nerve vascular damage by optical coherence tomography angiography

Purpose The aim of this study was to compare the macular and optic nerve head vessel perfusion density in mild primary open-angle glaucoma (POAG) and moderate–severe POAG patients to normal eyes as a control cohort. Patients and methods This is a retrospective comparative case–control study that included 80 eyes of 46 participants. The study included 60 eyes of 36 POAG patients and 20 eyes of 10 healthy participants (control group). The patients underwent 3.0×3.0 mm optical coherence tomography angiography (OCTA) scans centered on the macula and 4.5×4.5 mm scans on the optic disc. Results The OCTA scans of the glaucomatous eyes revealed a reduction in microvasculature in the peripapillary area, which was absent in the control cohort. The whole disc vessel density (VD) was significantly less in the glaucomatous eyes (mean=38.02±8.74) compared to the control cohort (mean=50.41±2.58, P <0.001). The severity of glaucoma was linked to a decrease in macular VD percentage, with a mean superficial VD of 36.09±5.67 in the glaucoma cohorts and 46.64±5.53 in the control cohort ( P <0.001), which was more pronounced than in the deep layer ( P <0.008). There was no statistically significant difference in the foveal avascular zone size between the control and glaucoma cohorts at any stage ( P =0.999). Conclusion The OCTA vascular density accurately distinguished the glaucoma from healthy eyes, with superior performance in the peripapillary region. The foveal avascular zone size did not indicate glaucoma severity. The OCTA noninvasive assessment of the capillary networks showed a potential for managing the glaucoma patients by characterizing the retinal vascular changes.