Peripapillary and parafoveal microvascular changes in eyes with optic neuritis and their fellow eyes measured by optical coherence tomography angiography: an Exploratory Study

Abstract

Purpose: This study aimed to evaluate parafoveal and peripapillary microvascular alterations in eyes with optic neuritis (ON) along with their fellow eyes compared to healthy control eyes using optical coherence tomography angiography (OCT-A). Methods: We included 31 ON-affected eyes and 31 fellow eyes of 31 patients who had experienced unilateral ON and 33 eyes of 33 healthy controls in this exploratory retrospective cross-sectional study. Optical coherence tomography angiography (OCT-A) was used to generate microvascular structural images and quantify the vessel density of the superficial retinal capillary plexus (SRCP), the deep retinal capillary plexus (DRCP) and radial peripapillary capillary (RPC) segments. We used the Kruskal–Wallis test for the comparison of OCT-A results between the three groups and generalized estimating equation models for the pairwise comparisons. Results: There were significant differences of SRCP (p = 0.0003) and RPC segment (p < 0.0001) vessel densities between the three groups. Specifically, there was a reduction in parafoveal and peripapillary vessel density in the ON-affected eyes compared to fellow eyes (SRCP, estimates, −1.97, 95% confidence interval [CI], −3.07, −0.87; RPC, −6.95, 95% CI, −8.70, −5.19) and controls (SRCP, −3.15, 95% CI, −4.61, −1.69; RPC, −8.66, 95% CI, −10.55, −6.76). The superior sector of the RPC segments vessel density in the fellow eyes was decreased compared to the controls (−4.93, 95% CI, −8.07, −1.80). Conclusions: The results of this study suggest that microvascular changes occur in both the affected eye and unaffected fellow eye after a unilateral ON episode. Future studies are needed to clarify the clinical implications of these findings.