Mild orbital optic nerve enhancement tied to poor visual outcomes in MOG-related optic neuritis

A milder enhancement in the orbital optic nerve appears to result in poorer visual acuity (VA) and visual field recovery among eyes with first myelin oligodendrocyte protein (MOG)-related optic neuritis (ON), a study has found.

In this cross-sectional study, the researchers identified patients who met the 2023 criteria for MOG antibody-associated disease who were seen for first episodes of MOG-related ON at three tertiary neuro-ophthalmology practices between January 2017 and July 2023. Eligible participants underwent contrast-enhanced, fat-suppressed MRI of the brain and orbits within a month of symptom onset.

Ninety-two patients (median age 37.0 years, 65.2 percent female), including 129 eyes, were included. Of these, 6.2 percent had poor VA outcome, 19.4 percent had incomplete VA recovery, and 16.8 percent had poor visual field mean deviation (VFMD) outcome.

Eyes with mild orbital optic nerve enhancement were more likely to have poor VA outcome (odds ratio [OR], 8.57, 95 percent confidence interval [CI], 1.85–51.14; p=0.009), incomplete VA recovery (OR, 7.31, 95 percent CI, 2.42–25.47; p=0.001), and poor VFMD outcome (adjusting for time to treatment: OR, 6.81, 95 percent CI, 1.85–28.98; p=0.005; adjusting for nadir VFMD: OR, 11.65, 95 percent CI, 1.60–240.09; p=0.04) than eyes with moderate-to-severe enhancement.

In addition, the lack of optic nerve sheath enhancement correlated with incomplete VA recovery (OR, 3.86, 95 percent CI, 1.19–12.85; p=0.02) relative to the presence of enhancement. These associations persisted in subgroup analysis of MRIs performed before initiation of treatment, but not in pairwise analysis of MRIs performed after treatment.

“Prospective and mechanistic studies are needed to confirm the prognostic usefulness of MRI in MOG-associated ON,” the researchers said.