Diffusion-weighted Imaging And Retinal Oximetry Predict Functional Outcome After The First Episode Of Optic Neuritis

Purpose: To evaluate diffusion weighted imaging (DWI) with advanced diffusion models, optical coherence tomography (OCT), and automatic retinal oximetry as potential biomarkers for visual deficits after optic neuritis (ON). Methods: Twenty-five patients with acute unilateral ON underwent brain DWI, OCT, and oximetry at the treatment initiation, and 3 and 6 months later. Additionally, 56 healthy volunteers with normal vision were examined once. Clinical outcomes were best-corrected visual acuity (BCVA) and contrast sensitivity. Predictors included retinal nerve fiber layer (RNFL) thickness, arteriolar and venular oxygen saturation (AS, VS), and arterio-venous difference (AVD) in the affected eye as well as DWI parameters from both optic radiations. Results: Multivariate analysis of variance (MANOVA) for baseline DWI indicated higher secondary partial volume fraction (f2) in patients, while both groups exhibited significant left-right differences for all DWI parameters. Longitudinal analysis in 17 patients with follow-up data revealed a multivariate effect of time when adjusted for affected side and time since onset, however, no DWI parameters changed significantly on a univariate level. Stratified unadjusted model indicated lower overall fractional anisotropy (FA) in patients with incomplete recovery. On uncorrected level, baseline FA and oximetry (VS) were correlated with follow-up BCVA at month 6, while axonal diffusivity (AD) predicted follow-up VS and AVD. In turn, baseline VS and AVD predicted follow-up RNFL thickness. Conclusions: DWI and retinal oximetry are promising early predictors of visual function outcome after ON. Translational Relevance: DWI and retinal oximetry are potentially suitable for patient stratification in studies investigating novel therapeutic interventions.