Non-invasive tryptophan fluorescence measurements as a novel method of grading cataract. (December 2017)

• Record Type: Journal Article
• Authors: Erichsen, Jesper Høiberg; Mensah, Aurore; Kessel, Line
• Is Part Of: Experimental eye research. Volume 165(2017)
• Page Start: 59
• Page End: 64
• Publication Date: 2017-12
• Subjects: Cataract -- Non-invasive -- Grading -- Tryptophan -- Fluorescence -- Scheimpflug; FLACS Femtosecond laser assisted cataract surgery -- PBS phosphate buffered saline -- PMT photomultiplier tube -- PSC posterior subcapsular cataract -- DLS dynamic light scattering -- NFK N-formylkynurenine -- OH-Trp hydroxytryptophan -- ArgP argpyrimidine; Ophthalmology -- Periodicals; Eye -- Periodicals; Œil -- Périodiques; Ophthalmology; Periodicals; Electronic journals; 612.8405
• DOI: 10.1016/j.exer.2017.09.006
• Languages: English
• ISSNs: 0014-4835

Abstract

Abstract: Development of non-invasive treatments for cataract calls for a sensitive diagnostic assay. We conducted a study to test whether the ratio of folded tryptophan to non-tryptophan fluorescence emission (F-factor) may be used for grading cataracts in human lenses. The F-factor was measured on aspirated lens material from eyes undergoing femtosecond laser assisted cataract surgery (FLACS) and was compared to a preoperative optical grading of cataract using Scheimpflug imaging. The preoperative optical grading allocated the cataracts to 1 of 4 categories according to the density of the cataract. All cataracts were age-related. Lens material from 16 eyes of 14 patients was included in the study. Cataracts were preoperatively graded in categories 1, 2 and 3. No lenses were category 4. For nuclear cataracts mean values of F-factor were 52.9 (SD 12.2), 61.7 (SD 5.3) and 75.7 (SD 8.9) for categories 1, 2 and 3 respectively. Linear regression on F-factor as a function of preoperative grading category showed increasing values of F-factor with increasing preoperative grading category, R 2 = 0.515. Our experiment showed that preoperative optical grading of cataracts by Scheimpflug imaging may correlate to measures of tryptophan and non-tryptophan fluorescence in human lenses. Based on our results we find that measuring the ratio between tryptophan- and non-tryptophan fluorescence may be a future tool for grading cataracts, but further research is needed. Highlights: Tryptophan fluorescence is a non-invasive biochemical diagnostic assay for cataract. Such assays are needed for evaluating emerging, non-invasive treatments of cataract. Fluorescence measures correlates to optical grading of cataracts. Tryptophan fluorescence measures is a potential future tool for evaluating cataracts.