Fig. 1.

Course of visual acuity of the affected eye (n = 18). Visual acuity prior to glucocorticosteroid treatment (GC), prior to initiation of plasma exchange (PLEX), i.e. after GC treatment, and after PLEX. Overlapping values of individual patients are not represented separately, single lines may thus represent more than 1 patient. For n = 1 patient with bilateral optic neuritis, the worse eye was included in the analysis. Matched observations were tested with the Friedman multiple comparison test. n.s., not significant; p value for significant findings <0.0001.