Optical coherence tomography angiography features of optic nerve head drusen and nonarteritic anterior ischemic optic neuropathy

Abstract

To evaluate the optic disc microvasculature in optic nerve head drusen (ONHD) vasculature in comparison to acute nonarteritic anterior ischemic optic neuropathy (NAION) and normal eyes using optical coherence tomography angiography (OCT-A). Ten eyes with ONHD, 10 eyes with acute NAION, and 10 healthy eyes were included in this prospective, comparative, observational case series. OCT-A imaging was performed on the optic discs. Qualitative grading was performed for dilation and tortuosity of the peripapillary vessels by 3 graders. Quantitative comparison was performed for peripapillary and inside disc vessel densities in nerve head (NH) and retinal peripapillary capillary (RPC) slabs. The intergrader agreement for dilation and tortuosity of the peripapillary vessels was poor (0.313 and 0.182 for vascular dilation in nerve head and radial peripapillary capillary enface images, respectively, and 0.478 and 0.490 for vascular tortuosity in nerve head and radial peripapillary capillary enface images, respectively). In NH en face images, the vessel density measurements were statistically significantly different between the 3 groups (all p < 0.05). In RPC en face images, the vessel density measurements were statistically significantly different between the 3 groups (all p < 0.05) except for nasal peripapillary sector (0.08). Despite poor intergrader agreement in qualitative analysis, quantitative OCT-A evaluation may differentiate optic disc edema due to NAION from pseudodisc edema due to ONHD.