Optical Coherence Tomography Angiography in Patients with Focal, Diffuse, and Sclerotic Glaucomatous Optic Discs

Abstract

Purpose : To examine peripapillary vessel density measurements in glaucoma eyes with focal, diffuse, and sclerotic glaucomatous damage.

Methods : The study included 143 eyes of 143 patients with repeatable visual field defect and glaucomatous optic neuropathy. All eyes underwent optic disc digital photography, standard automated perimetry (SAP), spectral-domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (OCT-A). Optic disc photographs were reviewed by 2 masked observers (AHM and AC) and classified into focal, diffuse, and sclerotic patterns of disc damage. If a disc didn’t fit into one of these categories, it was labeled “other” and excluded from further analysis. In cases of disagreement, a third masked observer (RNW) adjudicated. Peripapillary microvasculature was measured by OCT-A global and sectoral (6 sectors) vessel density as the percentage of area occupied by flowing vessels. To assess focal microvascular loss, the difference in OCT-A sectoral vessel density between the sector with the lowest measurement and the mean of the remaining 5 sectors was measured and compared between various disc phenotypes.

Results : Thirty-six (25.2%) eyes were classified into the focal, 50 (35.0%) into the diffuse, and 31 (21.7%) into the sclerotic group. 26 (18.2%) were judged as “other”. There was no statistically significant difference in the mean visual field mean deviation (VF MD) (P=0.4) and mean global retinal nerve fiber layer thickness (P=0.7) between the three groups. Peripapillary vessel density in eyes with sclerotic damage (mean 49.4%) was lower than in eyes with focal (mean 54.4%) and diffuse (mean 53.1%) optic disc damage (P=0.005). Eyes with focal damage had a larger sectoral microvascular vessel density difference between the sector with the lowest measurement and the remaining 5 sectors compared to the diffuse and sclerotic group (11.1%, vs. 9.5% and 9.8%, respectively), although this difference did not reach a statistical difference (p=0.292).

Conclusions : Eyes with sclerotic damage might have greater peripapillary circulatory abnormalities. OCT-A might enhance our understanding of the role of ocular vasculature in the pathophysiology of glaucoma.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.