Contributed Session III: Preclinical & clinical evaluation of flavoprotein fluorescence as a label-free biomarker of retinal mitochondrial stress.

Abstract

Retinal oxidative stress is linked to the development and progression of various retinal diseases including AMD and glaucoma. In response to oxidative stress, flavoproteins within the electron transport chain become oxidized and autofluoresce upon blue light exposure. We investigated the specificity of flavoprotein fluorescence (FPF) to mitochondrial oxidative stress in retinal cells in vitro and its reliability as a clinical biomarker for longitudinal monitoring of glaucoma. Preclinical FPF evaluation assessed mitochondria-specific FPF and reactive oxygen species (ROS) in retinal cells via confocal microscopy to characterize response to injury and oxidative stress perturbations. FPF intensity was directly correlated with increased stress-induced mitochondrial ROS (R2=0.693), confirming FPF signal origin. Clinical FPF measurements were evaluated using the OcuMet Beacon, a noninvasive retinal metabolic imaging device. FPF images were collected at macular and peripapillary regions of patients with stable glaucoma or glaucoma suspects (n=52) during baseline and three-month follow-up visits. Macular and peripapillary FPF scores showed strong correlation between patient baseline and follow-up measurements (r=0.996, lens-adjusted r=0.937, 0.972). These results confirm the relationship between FPF and oxidative stress in retinal cells and highlight FPF as a reproducible clinical imaging biomarker, supporting further discovery in rodent disease models and additional patient cohorts.