Vessel density calculated from OCT angiography in 3 peripapillary sectors in normal, ocular hypertensive, and glaucoma eyes

Purpose: Disturbed peripapillary microcirculation may have a role in the development of glaucoma. Recently, using noninvasive optical coherence tomography (OCT) angiography with the AngioVue OCT (Optovue Inc., Fremont, CA, USA), reduced peripapillary vessel density was found in glaucoma. In this case series, we investigate the relationship between retinal nerve fiber layer (RNFL) damage and peripapillary angioflow density (PAFD, % of the analyzed retinal area) in the superotemporal (ST), inferotemporal (IT), and temporal (T) peripapillary sectors in normal, ocular hypertensive (OHT), and primary open-angle glaucoma eyes. Case report: The AngioVue OCT and the 2015.100.0.33 software version was used for PAFD measurements. The PAFD in the radial peripapillary capillary layer was similar (approximately 60%) in all 3 sectors in healthy eyes. In glaucoma with severe ST and/or IT RNFL defect, PAFD declined to 32%-45% in the damaged sectors but remained above 55% in the T sector. In the OHT eyes with no visual field defect and no RNFL sector outside the normal limits but with mild ST or IT RNFL damage, PAFD declined to 54% in the involved sector in all cases, while it remained around 60% in the other sectors. Conclusions: Our cases suggest that PADF measurements can identify decreased peripapillary perfusion early in the glaucomatous RNFL thinning process, prior to the development of clinically significant RNFL damage and visual field deterioration. Decreased PAFD corresponds spatially with the damaged RNFL bundles. The results suggest that prospective studies using PAFD may help to understand the role of vascular dysfunction in glaucoma.