Interrogation of Retinal Lipofuscin by Fluorescence Lifetime Imaging Microscopy.

Age-related macular degeneration is a disease that affects the middle part of the vision and involves pathological alterations in the retinal pigment epithelium. Accurate and timely evaluation of the retinal pigment epithelium is a cornerstone of effective treatment planning. In this study, we present the development of a preclinical method for early diagnostics of age-related macular degeneration using time and spectral characteristics of fluorescence of lipofuscin granules from the retinal pigment epithelium. Using the unique system based on a superconducting single-photon detector and time-correlated single-photon counting electronics integrated in the confocal laser scanning microscope we determined the parameters of fluorescence (distribution long and short fluorescence lifetime components and their contribution to the total fluorescence signal as well as fluorescence spectral shift) that have a diagnostic value for differentiation of the normal and pathological states in the degenerative diseases of the retina and retinal pigment epithelium.