Influence of Lens Fluorescence on Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) Fundus Imaging and Strategies for Its Compensation.
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ABSTRACT: Purpose:To explore the contribution of crystalline lens fluorescence to fluorescence lifetimes measured with fluorescence lifetime imaging ophthalmoscopy (FLIO) and to propose a computational model to reduce the lens influence. Methods:FLIO, which detects autofluorescence decay over time in a short-wavelength spectral channel (SSC, 498-560 nm) and a long-wavelength spectral channel (LSC, 560-720 nm), was performed on 32 patients before and after cataract extraction. The mean autofluorescence lifetime (? m ) of the fundus was determined from a three-exponential fit of the postoperative fluorescence decays. The preoperative measurements were fit with series of exponential functions in which one fluorescence component was time-shifted in order to represent lens fluorescence. Results:Postoperatively, ? m was 185 ± 22 ps in the SSC and 209 ± 34 ps in the LSC at the posterior pole. These values were best reproduced by fitting the postoperative measurements with a three-exponential model with a time-shifted third fluorescence component (SSC, 203 ± 45 ps; LSC, 215 ± 29 ps), whereas disregarding time-shifted lens fluorescence resulted in significantly (P < 0.001) longer ? m values (SSC, 474 ± 206 ps; LSC, 215 ± 29 ps). The fluorescence of the cataract lens contributed to the total fluorescence by 54.2 ± 10.6% (SSC) and 29.5 ± 9.9% (LSC). Conclusions:Cataract lens fluorescence greatly alters fluorescence lifetimes measured at the fundus by FLIO, resulting in an overestimation of the lifetimes; however, this may be compensated for considerably by taking lens influence into account in the fitting model. Translational Relevance:This study investigates cataract fluorescence in FLIO and a mathematical model for compensation of this influence.
SUBMITTER: Brauer JL
PROVIDER: S-EPMC7422756 | biostudies-literature | 2020 Jul
REPOSITORIES: biostudies-literature
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