Predictors of Long-Term Visual Acuity in a Modern Cohort of Patients With Acute Idiopathic and Multiple Sclerosis–Associated Optic Neuritis

Abstract

Background: For patients with idiopathic or multiple sclerosis (MS)–associated optic neuritis (ON), the largest multicenter clinical trial (Optic Neuritis Treatment Trial [ONTT]) showed excellent visual outcomes and baseline high-contrast visual acuity (HCVA) was the only predictor of HCVA at 1 year. We aimed to evaluate predictors of long-term HCVA in a modern, real-world population of patients with ON and compare with previously published ONTT models. Methods: We performed a retrospective, longitudinal, observational study at the University of Michigan and the University of Calgary evaluating 135 episodes of idiopathic or MS-associated ON in 118 patients diagnosed by a neuro-ophthalmologist within 30 days of onset (January 2011–June 2021). Primary outcome measured was HCVA (Snellen equivalents) at 6–18 months. Multiple linear regression models of 107 episodes from 93 patients assessed the association between HCVA at 6–18 months and age, sex, race, pain, optic disc swelling, symptoms (days), viral illness prodrome, MS status, high-dose glucocorticoid treatment, and baseline HCVA. Results: Of the 135 acute episodes (109 Michigan and 26 Calgary), median age at presentation was 39 years (interquartile range [IQR], 31–49 years), 91 (67.4%) were women, 112 (83.0%) were non-Hispanic Caucasians, 101 (75.9%) had pain, 33 (24.4%) had disc edema, 8 (5.9%) had a viral prodrome, 66 (48.9%) had MS, and 62 (46.6%) were treated with glucocorticoids. The median (IQR) time between symptom onset and diagnosis was 6 days (range, 4–11 days). The median (IQR) HCVA at baseline and at 6–18 months were 20/50 (20/22, 20/200) and 20/20 (20/20, 20/27), respectively; 62 (45.9%) had better than 20/40 at baseline and 117 (86.7%) had better than 20/40 at 6–18 months. In linear regression models (n = 107 episodes in 93 patients with baseline HCVA better than CF), only baseline HCVA (β = 0.076; P = 0.027) was associated with long-term HCVA. Regression coefficients were similar and within the 95% confidence interval of coefficients from published ONTT models. Conclusions: In a modern cohort of patients with idiopathic or MS-associated ON with baseline HCVA better than CF, long-term outcomes were good, and the only predictor was baseline HCVA. These findings were similar to prior analyses of ONTT data, and as a result, these are validated for use in conveying prognostic information about long-term HCVA outcomes.