Fundus spectrophotometric studies by Delori et al.1,2 have shown that fundus autofluorescence (FAF) in vivo is mainly derived from retinal pigment epithelium (RPE) lipofuscin. In the past, lipofuscin accumulation has been largely studied in vitro using fluorescence microscopic techniques.3–5 Excessive accumulation of lipofuscin represents a common pathogenetic pathway in various complex retinal diseases and is believed to precede photoreceptor degeneration.6