Song H, et al. - In patients with Stargardt disease type 1 (STGD1) at a cellular level, researchers studied the spatial distribution of photoreceptor, retinal pigment epithelial (RPE), and autofluorescence (AF) abnormalities. To compare the cones, rods, and RPE cells between 3 patients with STGD1 and 1 control individual, cross-sectional study using fluorescence adaptive optics scanning light ophthalmoscopy was conducted. According to findings, high-resolution adaptive optics images of cones, rods and RPE cells on the leading disease front of STGD1 macular atrophy display an AF pattern that appears to colocalize with photoreceptors or may result from a combination of RPE cells and photoreceptors with AF signals. This in vitro observation is compatible with fluorescence histological reports from STGD1 photoreceptors. Detecting bisretinoid accumulation in photoreceptors can be an early pathological phase in STGD1 and can provide an in vivo imaging tool to act as a progression biomarker for the disease.