Comparison of vision-related quality of life in NMOSD and MOGAD

Background: Aquaporin-4 antibody positive neuromyelitis spectrum disorder (AQP4+ NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) are both associated with vision loss due to optic neuritis (ON), although evidence suggests more severe structural damage in NMOSD. The validated National Eye Institute Visual Function Questionnaire (VFQ) may be used to evaluate patients' perceptions of how vision impairment affects their lives. Objective: To compare vision-related quality of life in AQP4+ NMOSD and MOGAD using the NEI-VFQ. Methods: Participants with AQP4+ NMOSD and MOGAD, 18 years of age and older, were enrolled through the Canadian NMOSD and other atypical demyelinating diseases cohort study (CANOPTICS) at six Canadian centers and consented to enter the patient-reported outcomes sub-study. Participants completed the VFQ at study entry. We compared composite VFQ scores and subscale scores in all participants with NMOSD and MOGAD, those with a history of any ON, and those with a history of bilateral simultaneous ON. We used a multivariable linear regression model to evaluate the association of VFQ composite score with disease type (NMOSD versus MOGAD), age, sex at birth, disease duration, history of unilateral ON, history of bilateral ON, and visual functional system score (FSS). Results: There were 58 NMOSD participants, 49 (84.5 %) female, mean (SD) age 48.6 (14.8) years, and 42 MOGAD participants, 27 (64.3 %) female, mean (SD) age 45.2(15.1) years. Thirty-five (60.3 %) participants with NMOSD had a history of any ON and 11(19.0 %) of bilateral ON. For MOGAD, 30 (71.4 %) participants had a history of any ON and 14 (33.3 %) of bilateral ON. Mean (SD) VFQ composite scores were 82.2 (17.9) in NMOSD and 83.7 (17.6) in MOGAD for the full cohort; 75.0 (19.9) in NMOSD and 80.4 (18.7) in MOGAD for those with any history of ON; and 70.2 (25.6) in NMOSD and 74.9 (21.8) in MOGAD for bilateral ON. Composite scores did not differ significantly between participants with NMOSD and MOGAD in the full cohort or ON sub-groups. However, history of bilateral ON (beta=-13.2, p = 0.0008) and higher visual FSS (beta=-4.9, p < 0.0001) were associated with lower VFQ composite scores. Conclusion: In this Canadian multi-center cohort, vision-related quality of life was impaired in both NMOSD and MOGAD, without significant differences observed in scores. Vision-related quality of life assessment offers unique insights into the functional impact of vision loss, and should be considered as an outcome measure to evaluate visual disability in NMOSD and MOGAD in addition to visual acuity.