Combining fluorescence lifetime with spectral information in fluorescence lifetime imaging ophthalmoscopy (FLIO)

Blood vessels, macula, optic disc, and retinal pigment epithelium separated by the combination of fluorescence lifetime and peak emission wavelength in a young and healthy subject.

Fluorescence lifetime imaging ophthalmoscopy (FLIO) provides information on fluorescence lifetimes in two spectral channels as well as the peak emission wavelength (PEW) of the fluorescence. Here, we combine these measures in an integral three-dimensional lifetime-PEW metric vector and determine a normal range for this vector from measurements in young healthy subjects. While for these control subjects 97 (±8) % (median (interquartile range)) of all para-macular pixels were covered by this normal vector range, it was 67 (±55) % for the elderly healthy, 38 (±43) % for age-related macular degeneration (AMD)-suspect subjects, and only 6 (±4) % for AMD patients. The vectors were significantly different for retinal pigment epithelium (RPE) lesions in AMD patients from that of non-affected tissue (p < 0.001). Lifetime- PEW plots allow to identify possibly pathologic fundus areas in subjects as well as tracing the changes in fluorescence parameters over disease progression.

The open access publication was honored by the publisher with a "Spotlight on Optics".

M. Hammer, R. Simon, D. Meller and M. Klemm:

Combining fluorescence lifetime with spectral information in fluorescence lifetime imaging ophthalmoscopy (FLIO).
Biomedical Optics Express, vol. 13 (10), pp. 5483-5494, Sep 26 2022.

https://doi.org/10.1364/BOE.457946

Contact:    Dr.-Ing. Matthias Klemm