Determinants of vision-related quality of life in recessive Stargardt disease

BACKGROUND/AIMS: To evaluate associations of sociodemographic and functional parameters with vision-related quality of life (VRQoL) in recessive Stargardt disease (STGD1). METHODS: A total of 71 participants (42 females, 29 males; mean age 44±19 years) with genetically confirmed STGD1 were included in this cohort study. Two validated patient-reported outcome measures (PROMs), namely National Eye Institute Visual Function Questionnaire and Impact of Vision Impairment profile, were administered to the participants. Responses were analysed using latent trait models following psychometrically established dimension structures (functional and emotional subscales). Univariable and linear mixed-effects models were applied to investigate the association of putative determinants with VRQoL. RESULTS: The optimised models could predict the measured VRQoL impairment up to a multicollinearity-corrected adjusted accuracy of 0.558. Functional subscales could more accurately be predicted than emotional subscales. Overall, reading acuity was the most important determinant of VRQoL. Other functional parameters, including visual function of the worse eye, revealed significant impact as well while the influence of sociodemographic parameters on VRQoL was more inconsistent. CONCLUSIONS: The robust associations between VRQoL and visual function in STGD1 indicate that both PROM are suitable and construct valid outcome measures for upcoming interventional trials. Future clinical trials and patient assessment focusing on VRQoL might take near vision of both eyes into consideration.