Recurrent inflammatory optic neuropathy (RION)

Purpose Optic neuritis is a demyelinating inflammation of the optic nerve. Many cases of optic neuritis are associated with multiple sclerosis or neuromyelitis optica. In some cases, a recurrence of isolated optic neuritis is observed. However this existence of entity remains controversial. Yhe present retrospective study was designed to estimate the prevalence of this condition. Methods In five university hospitals (Lille, Montpellier, Nimes, Reims and Strasbourg), between October 2005 and October 2009, the charts of patients with recurrent isolated optic neuropathy (RION) and normal cerebral magnetic resonance imaging included prospectively were reviewed. The following parameters were analyzed: date of the first relapse, age at onset, duration at the time of inclusion, recurrence after steroid withdrawal, unilateral or bilateral involvement, number of relapses, visual acuity, retinal nerve fiber layer thickness, diagnostic workup, and longterm treatment with immunosuppressive or immunomodulatory drugs. Results During the predefined period, 18 patients (15 women, 3 men; age 17–54 years at onset) matched the inclusion criteria. Between two and six relapses of optic neuropathy were observed. The median duration was 6 years. In untreated patients (n=9), a significant inverse correlation was observed between visual acuity and duration of the disease; this correlation was not found in the group of patients (n=9) with long-term treatment Conclusion The progressive loss of vision over time in this retrospective study of recurrent isolated optic neuropathy could be related to axonal loss. A prospective cohort study is necessary to confirm this hypothesis and to evaluate the benefit of long-term treatment on this progression.