A Randomized Prospective Trial Comparing Repository Corticotropin Injection and Intravenous Methylprednisolone for Neuroprotection in Acute Optic Neuritis

Background:Repository corticotrophin injection (RCI, Acthar Gel) and intravenous methylprednisolone (IVMP) improve the rate but not the extent of visual recovery following acute optic neuritis. RCI has adrenal-stimulating and melanocortin receptor-stimulating properties that may endow it with unique anti-inflammatory properties relative to IVMP.Methods:Individuals with acute optic neuritis of less than 2 weeks duration were prospectively enrolled and randomized 1:1 to receive either RCI or IVMP. Peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell plus inner plexiform layer thickness (GC + IPL) were serially evaluated by OCT. In addition, patient-reported outcomes (PROs) for changes in fatigue, mood, visual function, depression, and quality of life (QOL) were measured, and high and low contrast visual acuity were recorded.Results:Thirty-seven subjects were enrolled (19 RCI; 18 IVMP); the average time from symptom to treatment was 8.8 days. At 6 months, there was no difference in the primary outcome: loss of average pRNFL thickness in the affected eye (RCI vs IVMP: -13.1 vs -11.7 µm, P = 0.88) 6 months after randomization. Additional outcomes also showed no difference between treatment groups: 6-month attenuation of GC + IPL thickness (RCI vs IVMP: -13.8 vs -12.0 µm, P = 0.58) and frequency of pRNFL swelling at 1 month (RCI vs IVMP: 63% vs 72%, P = 0.73) and 3 months (RCI vs IVMP: 26% vs 31%, P = 0.99). Both treatments resulted in improvement in visual function and PROs.Conclusions:Treatment of acute optic neuritis with RCI or IVMP produced no clinically meaningful differences in optic nerve structure or visual function.