RESUMEN
BACKGROUND: Optic neuritis (ON), a major cause of visual impairment in young adults, is generally associated with rapid visual recovery when treated with intravenous methylprednisolone treatment (IVMPT). However, the optimal duration of such treatment is unknown, ranging from three to seven days in clinical practice. We aimed to compare the visual recovery in patients treated with 5-day or 7-day duration IVMPT. METHODS: We performed a retrospective cohort study of consecutive patients with ON in São Paulo, Brazil, from 2016 to 2021. We compared the proportion of participants with visual impairment in 5-day and 7-day treatment schedules at discharge, at 1 month and between 6 and 12 months after the diagnosis of ON. The findings were adjusted to age, severity of the visual impairment, co-intervention with plasma exchange, time from symptom onset to IVMPT and the etiology of the ON to mitigate indication bias. RESULTS: We included 73 patients with ON treated with 5 or 7-day duration of 1 g/d intravenous methylprednisolone therapy. Visual impairment at 6-12 months in the 5-day or the 7-day treatment groups was similar (57% x 59%, p > 0.9, Odds Ratio 1.03 [95% CI 0.59-1.84]). The results were similar after adjusting for prognostic variables and when observed at different time points. CONCLUSION: Visual recovery is similar in patients treated with 5-day and 7-day duration treatments of 1 g/day intravenous methylprednisolone, suggesting a ceiling effect. Limiting the duration of the treatment can reduce hospital stay and costs, without interfering with clinical benefit.