JUL 11, 2019
This study presents the clinical and epidemiologic characteristics of optic neuritis in Japan.
The authors evaluated the epidemiology of optic neuritis in Japan in the era of aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibody (Ab) biomarkers. The retrospective study included 531 cases of noninfectious optic neuritis from 33 institutions in Japan between April 2015 and January 2018.
Sixty-six cases were AQP4-Ab positive, 54 were MOG-Ab positive, 1 was positive for both AQP4-Ab and MOG-Ab, and 410 were double negative. Fifteen patients in the double-negative group were diagnosed with multiple sclerosis. The AQP4-Ab positive group had a high proportion of females (84%) and 22% of the patients had visual acuity of counting fingers or worse. The MOG-Ab positive group experienced optic disc edema (76%) and pain with eye movements (77%) but had better recovery than the AQP4-Ab positive group; only 5% had count fingers or worse.
A multivariate analysis revealed that older age and AQP4-Ab were associated with worse visual outcomes, while MOG-Ab was associated with higher chance of recovery. Concurrent abnormalities on MRI, especially spinal cord lesions, were highest in the AQP4-Ab positive group and lowest in the MOG-Ab positive group.
Although the sample size was large and the cohort was drawn from multiple centers, this study was not a true population-based study. There may have been a bias toward more severe optic neuritis, thus increasing the percentage of AQP4-Ab and MOG-Ab cases. The retrospective study design also resulted in variable follow-up duration and treatments.
This study highlights the racial differences in optic neuritis. In this Japanese cohort, AQP4-Ab positive and MOG-Ab positive optic neuritis were more common than multiple sclerosis-associated optic neuritis. This is in stark contrast with Caucasian populations, where multiple sclerosis is the most common etiology. This study confirms that AQP4-Ab positive optic neuritis has the worst visual outcome, while MOG-Ab positive optic neuritis has better recovery and a favorable visual outcome.