Longitudinal Evaluation of Circumpapillary Structure-Function and Vasculature-Function Relationships in Acute and Sub-acute Nonarteritic Anterior Ischemic Optic Neuropathy

Abstract

PurposeTo investigate the global and regional correlations between longitudinal structure-function (S-F) and vasculature-function (V-F) using circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements, circumpapillary vessel density (cpVD) and the corresponding/final visual outcomes at different stages of nonarteritic anterior ischemic optic neuropathy (NAION). MethodsThirty eyes of 30 patients with acute NAION were included. LogMAR best-corrected visual acuity(BCVA), mean deviation (MD) and visual field index (VFI), cpRNFL thickness and cpVD across different retinal layers were examined at baseline, 2 weeks and 1 month after diagnosis. Potential correlations between the Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) parameters and visual outcomes were investigated in both acute and sub-acute NAION. ResultsSignificant global and regional correlations in S-F relationship were identified exclusively in sub-acute stage (p<0.05). However, among the OCTA parameters for the acute NAION, the temporal cpVD in superficial vessel complex (SVC) and inner retinal layer (IRL) exhibited positive correlations with corresponding and final visual acuity and visual field outcomes. In the sub-acute stage of NAION, the cpVD of global or temporal section in radial peripapillary capillary (RPC), SVC and IRL were positively correlated with visual outcomes. ConclusionSignificant longitudinal V-F relationships exist both globally and regionally, in acute and sub-acute NAION. The cpVD parameters of the SVC and IRL are potentially valuable for evaluating corresponding and final visual outcomes and highlights the importance of monitoring cpVD over cpRNFL thickness in acute NAION.