Our results are in line with 2 series describing corticosteroid and PE treatment in NMO optic neuritis. Nevertheless, our study stands out because of the delay in PE implementation after the patient was admitted to the hospital and intravenous corticosteroids had been administered. Those series have few optic neuritis cases (2 and 3 cases). Plasma exchange was performed approximately 2 weeks after attack onset in response to intravenous corticosteroid failure (between 3 and 6 g of methylprednisolone). Visual acuity improvement was observed soon after the implementation of PE, sometimes even after the first session.14,26 Garcia-Martin et al27 described a patient with NMO who presented with severe optic neuritis and experienced a quasi-complete recovery of visual function 6 months after treatment with intravenous injection of corticosteroids, PE, monoclonal antibodies, and immunosuppressors. Visual acuity recovery was also obtained by using double-filtration plasmapheresis. In the patient with NMO who was treated for bilateral optic neuritis, the PE had to be interrupted because of anaphylactic shock.15 Beside this observation, in most studies, the secondary effects associated with PE are not significant. Nevertheless, complications can be metabolic (hypocalcemia), infectious, allergic, central catheter related, or anticoagulation related (thrombotic and bleeding risk). Minor complications include those that are quickly reversible and easily treatable, such as arterial hypotension, fainting, or paresthesia. Major complications are anaphylactic reactions, respiratory arrest, and myocardial infarction. Plasma exchange requires extended surveillance, an appropriate infrastructure, and personnel trained in how to perform this technique.