gms | German Medical Science

Purpose: To investigate fluorescence lifetime characteristics in patients with age-related macular degeneration (AMD) and to correlate the measurements with clinical data and optical coherence tomography (OCT) findings.

Methods: Patients with either intermediate AMD or late AMD with geographic atrophy (GA) were imaged with a fluorescence lifetime imaging ophthalmoscope (Heidelberg Engineering, Germany). Autofluorescence lifetimes were measured in a short and a long spectral channel (498-560 nm and 560-720 nm).

Results: Fluorescence lifetime maps of 105 eyes of 105 patients (80±6 years) with GA (41) and intermediate AMD (64) were analyzed. Mean retinal autofluorescence lifetimes in patients with intermediate AMD was significantly prolonged compared with the healthy control eyes (mean±SEM: SSC, 486±18 vs. 332±11 ps, P < 0.0001; LSC: 493±9 vs. 382±17 ps, P < 0.0001). Areas of drusen featured a wide range of fluorescence lifetime values. Mean lifetimes within areas of atrophy were prolonged by 624±276 ps in the short spectral channel and 418±186 ps in the long spectral channel compared to the surrounding tissue. Autofluorescence lifetime abnormalities in GA occurred with particular patterns, similar to those seen in fundus autofluorescence intensity images.

Conclusions: This study established that autofluorescence lifetime changes in intermediate AMD and GA. Various autofluorescence lifetime pattern can be distinguished. Intraretinal deposits cause prolonged lifetimes, whereas deposits in the area of the outer photoreceptor segments lead to short fluorescence lifetimes. We hypothesize that the short lifetimes seen within the atrophy may be used to estimate damage induced by atrophy and may be useful to monitor disease progression in the context of natural history or interventional therapeutic studies.