Simvastatin improves final visual outcome in acute optic neuritis: a randomized study

Background: In recent years, small-scale clinical trials have indicated that statins or 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase inhibitors exert pleiotropic immunomodulatory effects, with potential therapeutic implications in multiple sclerosis (MS). Objective: To investigate whether simvastatin treatment (80 mg daily for 6 months) in patients with optic neuritis (ON) had a beneficial effect on visual outcome and on brain MRI. Methods: Sixty-four patients with acute ON were randomized to simvastatin treatment (n=32) or placebo (n=32) for 6 months. None of the patients had been on immunosuppressive therapy for 6 months prior to inclusion or treated with steroids from symptom onset. Contrast sensitivity (Arden plates), visual acuity, colour perception, visual evoked potentials (VEP) - latency and amplitude, Visual Analogue Scale (VAS) score, and gadolinium enhancing and T2 lesions on brain MRI were evaluated at screening visit, day 14 (except brain MRI), day 90 and day 180. Results: Simvastatin had a beneficial effect on VEP in both latency (p = 0.01) and amplitude (p = 0.01), a borderline effect on the Arden score (p = 0.06) and VAS (p = 0.04), and no effect on brain MRI or on relapse rate between the groups. Conclusion: This study provides Class I evidence that simvastatin 80 mg daily is well tolerated and possibly effective in patients with acute ON.