Figure 2. Kaplan-Meier estimates of time to motor and visual disability by AQP4-IgG serostatus.

(A) Years from onset to use of a cane (p = 0.43): at 5 years after onset, 28% of seronegative patients and 22% of seropositive patients were expected to need a cane to walk (EDSS score 6). (B) Years from onset to need for a wheelchair (p = 0.10): at 5 years after onset, no seronegative and 8% of seropositive patients were expected to be unable to walk and to need a wheelchair (EDSS score 8). (C) Years from onset to legal blindness in at least one eye (p = 0.34): at 5 years after onset, 57% of seronegative and 41% of seropositive patients were expected to be legally blind in at least one eye. (D) Years from onset to legal blindness in both eyes (p = 0.64): at 5 years after onset, 5% of seronegative and 9% of seropositive patients were expected to be legally blind in both eyes. (E) Years from onset to use of a cane for seropositive NMO (p = 0.07): at 5 years after disease onset, 36% TM-onset vs 14% ON-onset patients were expected to need a cane. (F) Years from onset to legal blindness in at least one eye for seropositive NMO (p = 0.09): at 5 years after disease onset, 39% of TM-onset vs 55% of ON-onset patients were expected to be legally blind in at least one eye. EDSS score 6 = intermittent or unilateral assistance (canes, crutches, or braces) required to walk 100 m with or without resting; EDSS 8 = restricted to bed or chair or perambulated in wheelchair but may be out of bed much of day, retains many self-care functions, generally has effective use of arms; legal blindness = sustained visual acuity of 20/200 or less with best correction possible for more than 6 months. AQP4 = aquaporin-4; EDSS = Expanded Disability Status Scale; IgG = immunoglobulin G; NMO = neuromyelitis optica; ON = optic neuritis; TM = transverse myelitis.