Share Email Print
cover

Journal of Biomedical Optics

In vivo measurement of time-resolved autofluorescence at the human fundus
Author(s): Dietrich Schweitzer; Martin Hammer; Frank Schweitzer; Roswitha Anders; Torsten Doebbecke; Stefan Schenke; E. R. Gaillard; Elizabeth R. Gaillard
Format Member Price Non-Member Price
PDF $20.00 $25.00

Paper Abstract

An experimental setup for measurement of time-resolved autofluorescence of the human eye fundus is demonstrated. The method combines laser scanning technique and time-correlated single photon counting. The light source is a laser diode, delivering pulses of about 100 ps duration at a repetition rate of 40 MHz. The excitation wavelength is 446 nm and the cutoff wavelength of fluorescence detection is at 475 nm. The autofluorescence can be determined with a spatial resolution of 80×80 μm2 and 25 ps time resolution. The fluorescence decay is optimally approximated by a biexponential model. The dominating lifetime τ1 is shortest in the macula (320 to 380 ps) and reaches 1500 ps in the optic disk. The lifetime τ2 varies between 2 ns and 5 ns, but the spatial distribution is more homogeneous. Respiration of 100% oxygen for 6 min leads to changes in the fluorescence lifetime pointing to detection of coenzymes. Diagrams of lifetime τ2 versus τ1 are well suited for comparison of substances. Such lifetime clusters of a 20 deg macular field of a young healthy subject and of a patient suffering from dry age-related macular degeneration overlap only partially with τ2-τ1 clusters of lipofuscin.

Paper Details

Date Published: 1 November 2004
PDF: 9 pages
J. Biomed. Opt. 9(6) doi: 10.1117/1.1806833
Published in: Journal of Biomedical Optics Volume 9, Issue 6
Show Author Affiliations
Dietrich Schweitzer, Univ. of Jena (Germany)
Martin Hammer, Friedrich-Schiller-Univ. Jena (Germany)
Frank Schweitzer, Friedrich-Schiller-Univ. Jena (Germany)
Roswitha Anders, Friedrich-Schiller-Univ. Jena (Germany)
Torsten Doebbecke, Friedrich-Schiller-Univ. Jena (Germany)
Stefan Schenke, Friedrich-Schiller-Univ. Jena (Germany)
E. R. Gaillard, Friedrich-Schiller-Univ. Jena (Germany)
Elizabeth R. Gaillard, Northern Illinois Univ. (United States)


© SPIE. Terms of Use
Back to Top