Natural history of the visual impairment of relapsing neuromyelitis optica

Purpose: To describe the clinical features and natural history of the visual impairment of relapsing neuromyelitis optica. Design: Prospective observational case series. Participants: Thirty patients of Afro-Caribbean origin with neuromyelitis optica.and 47 patients with multiple sclerosis. Methods: A complete ophthalmologic examination was performed with each ocular attack and during a remission period at least 6 months after the last attack. Main Outcome Measures: Incidence of unilateral and bilateral optic neuritis and incidence of unilateral and bilateral severe visual loss, defined as visual acuity (VA) <= 20/200. Results: Twenty-eight patients (93%) with neuromyelitis optica were female and 2 (7%) were male. The mean age of onset was 30-10.5 years. Mean disease duration was 9.5 +/- 5.4 years. Neuromyelitis optica first manifested by an episode of optic neuritis in 23 cases (76.6%), bilateral.in 4. The average number of ocular attacks per patient was 2.7 +/- 1.6. Twenty-one patients (70%) showed impairment in both eyes. Median times from onset to unilateral optic neuritis, -bilateral optic neuritis, mono-ocular severe visual loss, and binocular severe visual loss were 0 +/- 0.08,1 +/- 1.6, 2 +/- 0.8, and 13 +/- 3 years, respectively. Fifteen patients (50%) experienced severe visual loss in both eyes and 6 (20%) in one eye. Severe visual loss occurred in as few as 2 attacks. Conclusion: This study is the largest series of relapsing neuromyelitis optica in a population of African descent. Neuromyelitis optica's visual impairment is very severe; it, contrasts drastically with that typically observed in multiple sclerosis. We confirmed that the prognosis in patients with multiple sclerosis.