Early predictors of visual and axonal outcomes after acute optic neuritis

Minh N L Nguyen; Chao Zhu; Scott C Kolbe; Helmut Butzkueven; Owen B White; Joanne Fielding; Trevor J Kilpatrick; Gary F Egan; Alexander Klistorner; Anneke van der Walt

doi:10.3389/fneur.2022.945034

Early predictors of visual and axonal outcomes after acute optic neuritis

Front Neurol. 2022 Sep 8:13:945034. doi: 10.3389/fneur.2022.945034. eCollection 2022.

Authors

Minh N L Nguyen^{1

2}, Chao Zhu¹, Scott C Kolbe¹, Helmut Butzkueven^{1

2}, Owen B White^{1

2}, Joanne Fielding¹, Trevor J Kilpatrick³, Gary F Egan⁴, Alexander Klistorner⁵, Anneke van der Walt^{1

2}

Affiliations

¹ Department of Neurosciences, Monash University, Melbourne, VIC, Australia.
² Department of Neurology, Alfred Health, Melbourne, VIC, Australia.
³ Department of Neurology, Royal Melbourne Hospital, Melbourne, VIC, Australia.
⁴ Monash Biomedical Imaging, Monash University, Melbourne, VIC, Australia.
⁵ Save Sight Institute, University of Sydney, Sydney, NSW, Australia.

Abstract

Background: Predicting long-term visual outcomes and axonal loss following acute optic neuritis (ON) is critical for choosing treatment. Predictive models including all clinical and paraclinical measures of optic nerve dysfunction following ON are lacking.

Objectives: Using a prospective study method, to identify 1 and 3 months predictors of 6 and 12 months visual outcome (low contrast letter acuity 2.5%) and axonal loss [retinal nerve fiber layer thickness and multifocal evoked potential (mfVEP) amplitude] following acute ON.

Methods: In total, 37 patients of acute ON onset were evaluated within 14 days using between-eye asymmetry of visual acuity, color vision (Ishihara plates), optical coherence tomography, mfVEP, and optic nerve magnetic resonance imaging [magnetic transfer ratio (MTR) and diffusion tensor imaging (DTI)].

Results: Visual outcome at 6 and 12 months was best predicted by Ishihara asymmetry at 1 and 3 months following ON onset. Axonal loss at 6 and 12 months was reliably predicted by Ishihara asymmetry at 1 month. Optic nerve MTR and DTI at 3 months post-acute ON could predict axonal loss at 6 and 12 months.

Conclusions: Simple Ishihara asymmetry testing 1 month after acute ON onset can best predict visual outcome and axonal loss at 6 and 12 months in a clinical or research setting.

Keywords: Ishihara; MRI; OCT; optic neuritis; prognosis.