Comparison between optic neuritis associated with antibody against myelin oligodendrocyte glycoprotein and presumed idiopathic optic perineuritis

Background The aim of this study was to determine important clinical and radiological features that aid in distinguishing presumed idiopathic optic perineuritis (OPN) from optic neuritis (ON) associated with antibody against myelin oligodendrocyte glycoprotein (MOG-Ab). Methods This retrospective, case-control study recruited patients with MOG-Ab-associated ON from 2011 through 2018 and idiopathic OPN from 2009 through 2011. The presence of MOG-Ab was not investigated in idiopathic OPN, because MOG-Ab testing was not available until 2011. The clinical and radiological features and the disease course were compared between the two patient groups. Results A total of 48 patients with MOG-Ab-associated ON were identified. These included 15 patients showing optic nerve sheath enhancement (ONSE) and 33 with only optic nerve enhancement. Ocular pain with ocular movement and optic disc swelling were more common in patients with ONSE, who also exhibited a poorer initial visual acuity than did those without ONSE. However, the response to steroid treatment, incidence of relapse after steroid treatment, and visual outcome at the last visit were similar between subgroups. The clinical and radiological features and treatment outcome were similar between these patients with OPN and patients with MOG-Ab-associated ON with ONSE. On the other hand, the clinical features of MOG-Ab-associated ON without ONSE differed from those of idiopathic OPN. Conclusion Our findings showed a substantial proportion of ONSE in patients with MOG-Ab-associated ON. In view of the similarities between these patients and patients with OPN, MOG-Ab testing should be performed in all patients with idiopathic OPN.