Autofluorescence lifetime imaging of lipofuscin and oxidized melanin in retinal pigment epithelium cells
眼底视网膜色素上皮层细胞脂褐素及氧化黑色素自体荧光寿命成像研究

We report on our investigation of the spatial distribution and autofluorescence lifetime characterization of lipofuscin and oxidized melanin in the retinal pigment epithelium cells of the pig eye using a two-photon excitation fluorescence lifetime imaging microscopy (TPE-FLIM) system, which that is based on a time-correlated single photon counting technique. In particular, we analyzed the difference of autofluorescence lifetimes of these pigment granules in light-induced oxidizing environment. The experimental results showed that the fluorescence lifetime imaging can provide an effective differentiation of multi-component fluorophores, and fluorescence decay can be used to distinguish normal from abnormal fluorescence. TPE-FLIM has the potential to provide a high sensitive imaging instrument for the clinical diagnosis and pathological studies in ophthalmology, and is also of significance to the study of aging mechanism of cells in the fundus.