A Single-Center Retrospective Study Evaluating the Role of Therapeutic Plasma Exchange in Patients With an Initial Diagnosis of Optic Neuritis.

Few studies have explored the outcomes of patients with optic neuritis (ON) who undergo treatment with therapeutic plasma exchange (TPE). We hypothesized that patients with detectable antibodies may respond more favorably to TPE than those without. Data were retrospectively collected from the electronic medical record on patients ≥ 18 years old with a diagnosis of ON that our apheresis service consulted on between October 2022 and July 2024. A total of 288 admissions for ON occurred, and the apheresis service was consulted on 66 (23%); all patients were on high-dose steroids at the time of the consult. Fifty-four patients were diagnosed with neuromyelitis optica spectrum disorder (n = 24, 44%), myelin oligodendrocyte glycoprotein antibody-associated disease (n = 13, 24%), multiple sclerosis (n = 6, 11%), or ON not otherwise specified (n = 11, 20%). The mean age was 44 years, 74% were female, and 63% were Black. The average duration of visual symptoms prior to the initiation of TPE was 23 days; most patients underwent five TPE treatments, and the average improvement after the TPE course on a scale of 1-5 was 2.9. No relationship was observed between the duration of symptom onset prior to TPE and outcome, regardless of ON cause. Despite a long duration of symptoms prior to TPE, most patients showed moderate clinical improvement. The cause of ON or the presence of detectable antibodies did not impact the outcome, suggesting that removal by TPE of cytokines, complement, or other substances may be important.