ABCA4 and Stargardt disease: In this paper, we report an in vivo multimodal investigation using directional back-scattering (directional reflectivity) and SW-FAF, that reveals changes in the density of lipofuscin granules and melanosomes in the RPE of 14-month-old Abca4−/− mice (a model of Stargardt disease) relative to age-matched wild-type (WT) controls.