Objective: We identified fluorescence-lifetime ophthalmoscopy changes in Parkinson’s disease (PD) patients experiencing visual disturbances.

Background: Fluorescence-lifetime ophthalmoscopy (FLIO), a novel in vivo imaging method generating data for fluorescence decay in two spectral channels.  After an excitation frequency of 473 nm, FLIO acquires data from two channels of very short-lived chromophores: Channel 1 @ 498-560nm corresponding mostly to Nicotinamide adenosine dinucleotide hydrogen (“NADH”) and Flavin adenine dinucleotide (“FAD”) and channel 2 @ 560-720 nm corresponding primarily to lipofuscin. These data reflect the mitochondrial molecular environment.

Method: Eighteen participants [36 eyes], 9 PD patients experiencing visual disturbances and 9 controls, underwent FLIO imaging. Imaging was analyzed using SPCImage technology. The amplitude-weighted mean fluorescence decay time (τm) and mean channel wavelength were analyzed quantitatively using a nonparametric test based on Wilcoxon rank sum test followed by Steel-Dwass for post-hoc multiple comparisons.

Results: Significant differences were found in all mean channel wavelengths between PD patients and controls. Channels 1 and 2 for both eyes compared to controls displayed an overall right shift towards longer wavelengths. The amplitude-weighted mean fluorescence decay time was significantly (p<0.05) greater in channel 1 right eye, and channels 1 and 2 left eye.

Conclusion: FLIO detected changes consistent with alterations in the retinal mitochondrial molecular environment for both NADH and FAD as well as lipofuscin. FLIO is the only retinal imaging technique capable of detecting these changes. The FLIO data may help to explain the basis of visual disturbances in patients with PD. This technology, which is the in vivo equivalent of fluorescent lifetime imaging microscopy, may help to define mitochondrial dynamics in various stages of Parkinson’s Disease and may evolve into an objective biomarker for clinical trials.

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MDS Abstracts - https://www.mdsabstracts.org/abstract/fluorescence-lifetime-ophthalmoscopy-findings-in-parkinsons-disease-patients-with-visual-disturbances/