The fluorescence lifetime of lipofuscin granule fluorophores contained in the retinal pigment epithelium cells from human cadaver eyes in normal state and in the case of visualized pathology

Abstract

A comparative analysis of fluorescence lifetime of lipofuscin granule fluorophores contained in the retinal pigment epithelium cells from human cadaver eyes in normal state and in the case of visualized pathology was carried out. Measurements of fluorescence lifetimes of bis-retinoids and their photooxidation and photodegradation products were carried out using the method of counting time-correlated photons. Comparative analysis showed that, in the case of visualized pathology, the contribution of photooxidation and photodegradation products of bis-retinoids to the total fluorescence of the retinal pigment epithelium cell suspension increases in comparison with the norm.

Spectral analysis of fundus autofluorescence pattern as a tool to detect early stages of degeneration in the retina and retinal pigment epithelium

“…At the same time, the contribution A 3 of the exponential component τ 3 was about 7% higher for AMD than for normal eyes for detection at 540 nm and about 15% higher for detection at 620 nm. We previously showed that, in the chloroform extract of LGs, bisretinoid photooxidation and photodegradation products had the highest fluorescence lifetime values (τ 3 = 7.2 ± 0.3 ns) [49,50]. These findings suggest that, in evaluating RPE cell suspensions, the fluorophores with a fluorescence lifetime characterized by τ 3 values are also bisretinoid photooxidation and photodegradation products.…”

Fluorescence Lifetime Imaging Ophthalmoscopy of Mouse Models of Age-related Macular Degeneration

“…It is likely that the relative τ m prolongation observed in LSC in Nrf2 −/− mice is due to increased intracellular lipofuscin. The τ m of lipofuscin has been reported to be longer than 1000 ps, 8 , 51 and it is suggested that this factor is related to an age-related increase in the τ m of LSC in humans. 10 , 13 Suppression of cellular antioxidant function results in direct oxidative stress on cells, which leads to suppression of intracellular energy metabolism and organelle function, resulting in an increase in lipofuscin.…”

Lipofuscin, Its Origin, Properties, and Contribution to Retinal Fluorescence as a Potential Biomarker of Oxidative Damage to the Retina

“…It could be argued that the spectral shift of the emission maximum to shorter wavelengths is due to SDD, drusen, and other deposits, such as basal laminar deposit, which accumulate in the Bruch' membrane and are already known as prognostic factors for AMD progression [369,370]. While the contribution from such sub-RPE deposits can indeed contribute to the observed decrease in a wavelength corresponding to the fluorescence emission maximum, there is some evidence that this decrease is due to spectral changes in fluorescence of the RPE [371][372][373][374]. Feldman et al reported fluorescence spectra of suspensions of RPE cells from two normal eyes and two AMD eyes [371].…”

“…Normal RPE exhibited maxima at 563 and 564 nm, whereas the maxima for the RPE from AMD eyes were at 528 and 540 nm [371]. Follow up study using excitation with 488 nm laser of RPE cell suspensions from 19 normal eyes (age 27-74 years) and 12 AMD (age 59-88 years) demonstrated substantial spectral differences between the emission spectra of RPE from normal and AMD-affected eyes [372][373][374]. There was a clear emission maximum at 592 nm for normal RPE.…”