Abstract
Purpose :
Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a novel imaging modality used to investigate the retina. Benefit of using FLIO has been shown for a variety of different retinal diseases, but signals can be influenced by cataracts. This study aims to investigate this impact and to give a solution for data analysis.
Methods :
12 eyes from 10 subjects (mean age 67 ± 7 years) were included in this clinic-based, longitudinal, prospective study. Investigations were conducted at two time points: before cataract surgery (same day) as well as four weeks after intervention. All subjects underwent Heidelberg Engineering FLIO, OCT, and MP measurements (two-wavelength autofluorescence). FLIO lifetimes of a 30° retinal field as well as from the lens were detected in two spectral channels (SSC: 498-560 nm; LSC: 560-720 nm), and amplitude-weighted mean fluorescence lifetimes (tm) were calculated. These were used for further analysis.
Results :
Retinal FLIO lifetimes were shorter after cataract surgery. This was significantly notable in the SSC (entire macula: 617 ± 531 ps before surgery vs 219 ± 36 ps after surgery, p<0.05), but also detectable in the LSC (422 ± 183 ps vs 308 ± 15 ps, p=0.052). The impact of the lens across the retina was not uniform, the fovea was most strongly affected by the lens fluorescence. A different analytical approach using an increased offset may minimize this effect in some patients.
Conclusions :
FLIO lifetimes depend on the amount of lens opacification. Different approaches in FLIO analysis may be able to minimize this effect. FLIO lifetimes of the lens itself may give novel possibilities in better quantifying individual cataracts, possibly enhancing the decision making to refer a patient to surgery.
This is a 2020 ARVO Annual Meeting abstract.