Song H, et al. - Considering the criticality of targeting the early pathogenic steps in Stargardt disease type 1 (STGD1) to enhance understanding of this condition and to develop potential therapies, researchers examined if fluorescence adaptive optics scanning light ophthalmoscopy can produce autofluorescence (AF) images in vivo with microscopic resolution to clarify the cellular origin of AF abnormalities in STGD1. They conducted a cross-sectional study of high-resolution in vivo images of cones, rods, and retinal pigment epithelial cells in 3 individuals with STGD1. In the transition zone adjacent to clinically detectable retinal pigment epithelial atrophy, the pattern of autofluorescence images may arise from photoreceptors or represent a combination of autofluorescence signals from retinal pigment epithelial cells and photoreceptors. Findings suggest the mediatory role of accumulation of lipofuscin precursors in photoreceptors in the hyperautofluorescence at the leading disease front in STGD1 that may represent an early disease step in STGD1.