Despite recent advances in diagnosis and management, neuromyelitis optica spectrum disorder (NMOSD) remains a relatively rare and complex entity. Despite estimates for a wide range of countries, ^{Reference Hor, Asgari and Nakashima1} reliable estimates of prevalence, demographics and direct and indirect costs in Canada are lacking. One US study estimated the average annual cost per patient to be ∼$150,000 CAN, half being indirect costs. ^{Reference Osborne, Bernitsas and Rebeira2} Furthermore, to optimize care, we need a national holistic view of our multiethnic population’s journey through each province’s unique healthcare system, treatment protocols used and an estimate of conventional versus newer monoclonal treatments. The CANOPTICS study, a prospective registry enrolling patients with NMOSD and other atypical demyelinating diseases across Canada, was designed for these purposes. In the present study, ^{Reference Momen, Freedman and Fadda3} data from all seropositive NMOSD patients ≥ 18 with disease onset from 1990 to 2022 were analyzed. Multiple sociodemographic, comorbid, diagnostic, disease characteristic and disease management variables were included.

In 133 eligible patients (mean age 52 years), they found a high female preponderance (84.9%), and 33% were Caucasian, with ∼22% and 25% Asian and African/Caribbean, respectively. Over 63% had immigrated to Canada, 91% with their first attack afterward. Only 58% had antibody status confirmed by cell-based assay. First attacks were typically disabling (>75%), and ∼29% were unemployed due to disability. Azathioprine was the most commonly prescribed agent, even in recent years. Rituximab was more commonly used as second and third line and is currently first line in only ∼10%. Novel targeted monoclonals (first approved in Canada in 2019) were rarely used (29/133 patients and mostly second/third line), although most monoclonals are not approved first line in Canada despite highly positive trials. ^{Reference Holian and Weinshenker4}

Thus far, results are in keeping with other North American studies. ^{Reference Carlson, Sollero and Wolf5,Reference Briggs and Shaia6} This study revealed NMOSD’s significant impact on Canada’s immigrant population with marked disability, high unemployment and a concerning reliance on nonspecific immunosuppressive therapies that may reflect limited access and specialty care.

The CANOPTICS registry has many strengths as the first standardized national effort to index NMOSD in Canada, which will ideally lead to improved patient outcomes and resource allocation, and provide for better patient education and targeted advocacy. Limitations include missing country of origin data, using ELISA-based serostatus (this should improve with the wider adoption of cell-based assays) and missing patients too disabled or disenfranchised to attend and enroll.