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Purpose: To observe fundus autofluorescence (FAF) lifetimes and peak emission wavelength (PEW) of drusen with respect to the pathology of the overlying RPE in the follow‐up of AMD‐patients. Methods: Forty eyes of 38 patients (age: 75.1 ± 7.1 years) with intermediate AMD were included. FAF lifetimes and PEW were recorded by fluorescence lifetime imaging ophthalmoscopy (FLIO). Twenty‐six eyes had a follow‐up investigation between months 12 and 36, and 10 at months 37–72. AMD progression was retrieved from color fundus photography (CFP) and OCT. Drusen were classified with respect to changes in the overlying RPE into groups no, questionable or faint, and apparent hyperpigmentation based on CFP. Results: Among the 210 hyperautofluorescent drusen found at baseline, those with hyperpigmentation had longer lifetimes and shorter PEW than those without. Drusen without hyperpigmentation had shorter lifetimes and PEW than neighboring RPE (all p < 0.001) at baseline, but drusen lifetimes increased, and PEW shortened further over follow‐up. Eyes, showing AMD progression, had significantly longer FAF lifetimes at baseline than non‐progressing eyes: 282 ± 102 ps versus 245 ± 98 ps, p < 0.001 and 365 ± 44 ps vs. 336 ± 48 ps, p = 0.025 for short and long wavelength FLIO channel, respectively. Conclusions: Depending on hyperpigmentation properties, drusen show lifetimes and PEW different from that of adjacent RPE which change over the natural history of AMD. This difference and change, however, might reflect progressive dysmorphia of the RPE rather than representing fluorescence of drusen material itself. Nevertheless, the observed FAF changes could make FLIO a useful tool for the early detection of AMD progression risk. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the spectral characteristics of fundus autofluorescence (FAF) in AMD patients and controls. Methods: Fundus autofluorescence spectral characteristics was described by the peak emission wavelength (PEW) of the spectra. Peak emission wavelength (PEW) was derived from the ratio of FAF recordings in two spectral channels at 500–560 nm and 560–720 nm by fluorescence lifetime imaging ophthalmoscopy. The ratio of FAF intensity in both channels was related to PEW by a calibration procedure. Peak emission wavelength (PEW) measurements were done in 44 young (mean age: 24.0 ± 3.8 years) and 18 elderly (mean age: 67.5 ± 10.2 years) healthy subjects as well as 63 patients with AMD (mean age: 74.0 ± 7.3 years) in each pixel of a 30° imaging field. The values were averaged over the central area, the inner and the outer ring of the ETDRS grid. Results: There was no significant difference between PEW in young and elderly controls. However, PEW was significantly shorter in AMD patients (ETDRS grid centre: 571 ± 26 nm versus 599 ± 17 nm for elderly controls, inner ring: 596 ± 17 nm versus 611 ± 11 nm, outer ring: 602 ± 16 nm versus 614 ± 11 nm). After a mean follow‐up time of 50.8 ± 10.8 months, the PEW in the patients decreased significantly by 9 ± 19 nm in the inner ring of the grid. Patients, showing progression to atrophic AMD in the follow up, had significantly (p ≤ 0.018) shorter PEW at baseline than non‐progressing patients. Conclusions: Peak emission wavelength (PEW) is related to AMD pathology and might be a diagnostic marker in AMD. Possibly, a short PEW can predict progression to retinal and/or pigment epithelium atrophy. [ABSTRACT FROM AUTHOR]

Purpose: To determine the fundus autofluorescence (FAF) lifetimes and spectral characteristics of individual drusen and hyperpigmentation independent of those with retinal pigment epithelium (RPE) in geographic atrophy (GA) areas in late‐stage age‐related macular degeneration (AMD). Methods: Three consecutive patients with complete RPE and outer retinal atrophy (cRORA) exhibiting drusen that were calcified or associated with hyperpigmentation were investigated with multimodal non‐invasive ophthalmic imaging including colour fundus photography (CFP), optical coherence tomography (OCT), near‐infrared reflectance (NIR), blue FAF and fluorescence lifetime imaging ophthalmoscopy (FLIO). Fluorescence lifetimes were measured in two spectral channels (short‐wavelength spectral channel (SSC): 500–560 nm and long‐wavelength spectral channel (LSC): 560–720 nm). Results: Drusen lacking RPE coverage, as confirmed by CFP and OCT, had longer FAF lifetimes than surrounding cRORA by 127 ± 66 ps (SSC) and 113 ± 48 ps (LSC, both p = 0.008 in Wilcoxon test, N = 9) and by 209 ± 100 ps (SSC) and 121 ± 56 ps (LSC, p < 0.001, N = 14) in two patients. Hyperpigmentation in CFP in a third patient shows strong FAF with prolonged lifetimes. In the SSC, persistent FAF was found inside cRORA. A crescent‐shaped hyperfluorescence in an area of continuous RPE but lacking outer retina was seen in one eye with a history of anti‐VEGF treatment. Conclusions: Short‐wavelength fluorescence in cRORA points to fluorophores beyond RPE organelles. Fluorescence properties of drusen within cRORA differ from in vivo drusen covered by RPE. These limited findings from three patients give new insight into the sources of FAF that can be further elucidated in larger cohorts. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is known to be related to a perifoveal lengthening of fundus autofluorescence (FAF) lifetimes (Sauer et al., [2]). Over the follow-up, eight patients developed choroidal neovascularization (CNV), confirmed by fluorescein angiography, seven patients progressed to cRORA, and 32 patients remained at intermediate AMD. [Extracted from the article]

To distinguish those fluorophores, FAF can be characterized by its fluorescence lifetime and by its emission spectrum. Graph Dear Editor, Fundus autofluorescence (FAF) can arise from a variety of fluorophores. 2 Histogram of PEW distributions at the posterior pole (top) and fovea (bottom) over all patients (n = 32) before and after cataract extraction This indicates that FAF observations, even if using confocal scanning techniques, are overlaid by the lens fluorescence. [Extracted from the article]