Georgiou M, Kane T, Tanna P, et al. - In this prospective cohort study, researchers discovered the reliability and repeatability of quantitative evaluation of areas of decreased autofluorescence (DAF) from fundus autofluorescence (FAF) images and track disease progression in children with Stargardt disease (STGD1), and examined clinical and genotype associations, disease symmetry, and intrafamilial variability. Children and adults with molecularly validated STGD1 (n = 90) were subjected to longitudinal FAF imaging with subsequent semiautomated DAF area measurement and the annual rate of progression calculation. Based on the age at baseline and age of onset, patients were grouped for analysis, into children (n = 56), adults with childhood-onset STGD1 (n = 15), and adults with adult-onset (n = 19). In a cohort of molecularly confirmed children with STGD1, this is the first large prospective study of FAF. DAF area quantification was highly reliable and can thus act as a robust structural endpoint. In childhood-onset disease, a high rate of progression was observed making this subtype of STGD1 ideally suited for prioritization in clinical trials. Limited intrafamilial variability has been noted.