Real-world application of the 2022 diagnostic criteria for first-ever episode of optic neuritis.

Optic neuritis (ON) admits diverse differential diagnoses. Petzold proposed diagnostic criteria for ON in 2022, although real-world application of these criteria is missing. We conducted a retrospective review of patients with ON. We classified patients into definite or possible ON, and into groups A (typical neuritis), B (painless), or C (binocular) and estimated the frequency of etiologies for each group. We included 77 patients, with 62% definite and 38% possible ON. CRION and NMOSD-AQP4 negative-ON were less commonly seen in definite ON. Application of the 2022 criteria revealed a lower-than-expected frequency of definite ON, particularly for seronegative non-MS causes.