Researchers now believe that OCT angiography (OCT-A) can be a promising technology to noninvasively evaluate optic disc perfusion and help characterize peripapillary vascular changes in nonarteritic ischemic optic neuropathy (NAION). Their study found that retinal peripapillary vascularity is compromised in NAION eyes, but vascularity is not significantly affected at the choroidal level.
In their cross-sectional study, the team analyzed OCT-A images of the optic nerve head in 10 non-acute unilateral NAION patients and 12 healthy age-matched controls. The researchers compared the peripapillary retinal and choroidal vascularity of NAION eyes with fellow and control eyes.
The study found that mean total peripapillary superficial retinal vessel and perfusion density were significantly reduced in NAION eyes compared with fellow eyes (13.93mm−1 and 0.36 for NAION eyes; 17.77mm−1 and 0.43 for fellow eyes). Two analysis techniques yielded differing results: the ImageJ analysis found a 32% reduction in superficial retinal perfusion in NAION eyes, and the instrument's inbuilt algorithm found a 16% reduction compared with fellow and control eyes.
The researchers believe that a longitudinal study with close follow-up would better identify the serial changes in perfusion associated with NAION.
Dhiman R, Chawla R, Azad SV, et al. Peripapillary retinal and choroidal perfusion in nonarteritic ischemic optic neuropathy using optical coherence tomography angiography. Optom Vis Sci. July 29, 2020. [Epub ahead of print].