Fundus autofluorescence intensity, lifetime, and spectral imaging in age-related macular degeneration

Fundus autofluorescence (FAF) imaging is a well-established retinal imaging technique that is widely used in the diagnostics of age-related macular degeneration (AMD). It facilitates the classification of distinct autofluorescence patterns, which may be predictive of AMD progression, the quantification of atrophic zones and their development over time and serves as a clinical endpoint in various studies. However, beyond autofluorescence intensity, emission spectra and fluorescence lifetime can be utilized to further investigate specific fluorophores, their changes in association with AMD, and their potential prognostic value in disease progression and therapy monitoring. In this review, we present the current state of spectrally and temporally resolved retinal FAF imaging in AMD. We explain the underlying principles, review the applied techniques, propose possible fluorophores contributing to FAF, summarize results from clinical studies as well as from histology and investigations in both in vivo and in vitro AMD models, and discuss the limitations of current techniques along with perspectives for technical development and clinical application.