title: FLIMX: A Software Package to Determine and Analyze the Fluorescence Lifetime in Time-Resolved Fluorescence Data from the Human Eye.
abstract: Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a new technique for measuring the in vivo autofluorescence intensity decays generated by endogenous fluorophores in the ocular fundus. Here, we present a software package called FLIM eXplorer (FLIMX) for analyzing FLIO data. Specifically, we introduce a new adaptive binning approach as an optimal tradeoff between the spatial resolution and the number of photons required per pixel. We also expand existing decay models (multi-exponential, stretched exponential, spectral global analysis, incomplete decay) to account for the layered structure of the eye and present a method to correct for the influence of the crystalline lens fluorescence on the retina fluorescence. Subsequently, the Holm-Bonferroni method is applied to FLIO measurements to allow for group comparisons between patients and controls on the basis of fluorescence lifetime parameters. The performance of the new approaches was evaluated in five experiments. Specifically, we evaluated static and adaptive binning in a diabetes mellitus patient, we compared the different decay models in a healthy volunteer and performed a group comparison between diabetes patients and controls. An overview of the visualization capabilities and a comparison of static and adaptive binning is shown for a patient with macular hole. FLIMX's applicability to fluorescence lifetime imaging microscopy is shown in the ganglion cell layer of a porcine retina sample, obtained by a laser scanning microscope using two-photon excitation.
authors.affiliation: Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, POB 100565, 98694, Ilmenau, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Klemm
authors.affiliation: Experimental Ophthalmology, University Hospital Jena, Bachstraße 18, 07740, Jena, Germany.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Schweitzer
authors.affiliation: Experimental Ophthalmology, University Hospital Jena, Bachstraße 18, 07740, Jena, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Peters
authors.affiliation: Experimental Ophthalmology, University Hospital Jena, Bachstraße 18, 07740, Jena, Germany.
authors.forename: Lydia
authors.initials: L
authors.lastname: Sauer
authors.affiliation: Experimental Ophthalmology, University Hospital Jena, Bachstraße 18, 07740, Jena, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hammer
authors.affiliation: Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, POB 100565, 98694, Ilmenau, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Haueisen
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D016477:Artifacts; D003920:Diabetes Mellitus / Q000473:pathology; D005123:Eye / Q000166:cytology* / Q000473:pathology; D005260:Female; D005453:Fluorescence; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy / Q000379:methods*; D061848:Optical Imaging / Q000379:methods*; D012165:Retinal Ganglion Cells / Q000166:cytology; D012167:Retinal Perforations / Q000473:pathology; D012984:Software; D013552:Swine; D013997:Time Factors