Multifocal ERG reveals functional retinal changes in multiple sclerosis patients treated with teriflunomide: a 12-month prospective study

In multiple sclerosis (MS), the retina can be affected by acute inflammation during optic neuritis and by chronic neurodegeneration involving retinal cells. Teriflunomide is an approved immunomodulatory therapy that reduces relapse rates, but its potential to mitigate chronic retinal damage in MS remains unclear. We conducted a prospective, open-label study including 15 patients (87% females, mean ± SD age of 46.5 ± 6.2 years-old) with RRMS initiating teriflunomide as standard of care. Assessments were performed at baseline and after 12 months, including best-corrected visual acuity, neurological disability (Expanded Disability Status Scale, EDSS), retinal layer thickness by optical coherence tomography (OCT), and multifocal electroretinography (mfERG) to evaluate retinal cell function. During follow-up, patients remained clinically stable with no relapses, optic neuritis episodes, or significant changes in EDSS or visual acuity. After 12 months of treatment, mfERG analysis revealed a statistically significant overall wave amplitude mean increase in P1 (+ 21.6%, p = 0.039) and a non-significant mean increase in N1 (+ 17.5%, p = 0.143) and N2 amplitude (+ 11%, p = 0.851). One year of teriflunomide therapy was associated with functional improvement in retinal electrophysiological responses in clinically stable MS patients.