Non invasive live imaging of a novel retinal pigment epithelium stress model with Dynamic Full-Field Optical Coherence Tomography

TL;DR

This study demonstrates that dynamic full-field OCT (D-FFOCT) enables live, subcellular imaging of retinal pigment epithelium cells in stress conditions, offering potential for early diagnosis and treatment of degenerative retinal diseases.

Contribution

The paper introduces D-FFOCT as a novel technique for live, in vitro observation of RPE cells at subcellular resolution, specifically under stress conditions relevant to retinal diseases.

Findings

D-FFOCT can monitor RPE cell stress and wound healing.

Mitochondria are the main contributors to D-FFOCT signals.

D-FFOCT has potential for live diagnostics and treatment guidance.

Abstract

Retinal degenerative diseases lead to the blindness of millions of people around the world. In case of age-related macular degeneration (AMD), the atrophy of retinal pigment epithelium (RPE) precedes neural dystrophy. But as crucial as understanding both healthy and pathological RPE cell physiology is for those diseases, no current technique allows subcellular in vivo or in vitro live observation of this critical cell layer. To fill this gap, we propose dynamic full-field OCT (D-FFOCT) as a candidate for live observation of in vitro RPE phenotype. In this way, we monitored primary porcine and human stem cell-derived RPE cells in stress model conditions by performing scratch assays. In this study, we quantified wound healing parameters on the stressed RPE, and observed different cell phenotypes, displayed by the D-FFOCT signal. In order to decipher the subcellular contributions to these dynamic profiles, we performed immunohistochemistry to identify which organelles generate the signal and found mitochondria to be the main contributor to D-FFOCT contrast. Altogether, D-FFOCT appears to be an innovative method to follow degenerative disease evolution and could be an appreciated method in the future for live patient diagnostics and to direct treatment choice.