Aktuelle Tagungsinformationen
News and Updates
Anmeldung zur Tagung
Registration
Hotelbuchung
Hotel Registration
Grußwort
Welcome address
Beteiligte Gesellschaften
Societies involved
Eröffnung des Kongresses
Opening Ceremony
Preise
Awards
Wissenschaftliches Programm
Scientific program
Posterpräsentationen
Poster Presentation
Kurse
Courses
Begleitende Veranstaltungen
Collateral Events
Rahmenprogramm
Social program
Jubiläumsparty
Jubilee Party
DOG Information
DOG Information
Allgemeine Informationen
General Information
Autorenindex
Index of Authors
Ausstellerliste
Exhibitors
Sponsoren
Sponsors
Teilnahmegebühren
Registration fees
Impressum
DOG Homepage
Alterations of Autofluorescence Lifetime after Oxygen Provocation
Schweitzer D., Kolb A., Hammer M., Anders R.,
Friedrich-Schiller-Universität Jena, Klinik für Augenheilkunde, Experimentelle Ophthalmologie (Jena)
Purpose: In addition to known methods for detection of parameters of microcirculation like blood flow and oxygen saturation, the metabolism at cellular level should be evaluated.
Methods: Pyridines and flavins are co-enzymes in several metabolic branches (citrate acid cycle or oxidative phosphoryllation) and change their fluorescence properties between oxidised and reduced stage. Under conditions of measurements at the eye, fluorescence lifetime is a fingerprint of each substance, permitting a discrimination and documentation of fluorophores in fundus images as a "metabolic mapping". With a home-built arrangement, lifetimes between 0.1 and about 10 ns can be determined at the living fundus. Lifetime images are determined before and during 6 min. respiration of 100% oxygen as well as 15 min. after breathing normal air. For evaluation of changes, frequency distribution of lifetimes was considered of whole fundus, optic disc, and papillo-macular bundle. By this method, ranges of lifetimes in which alterations are provoked, can be determined and be presented in fundus images.
Results: In bi-exponential approximation of decay of fluorescence, the para-papillary region exhibit a homogenous fluorescence before provocation between 0.35 and 0.62 ns, but the fluorescence is reduced during oxygen respiration. No fluorescence is detectable from optic disc in this lifetime range. In contrast, only the optic disc is fluorescent between 0.7 and 1.2 ns before, but the whole fundus fluoresces after oxygen respiration. Between 3.5 and 4 ns, autofluorescence is detectable from optic disc only after oxygen provocation.
Conclusions: It was proven that an increased supply of tissue outside vessels by oxygen can be demonstrated by time resolved autofluorescence. New information, related to metabolism, are expected in investigation of glaucoma, AMD, and diabetic retinopathy by time resolved autofluorescence.