(714) Noninvasive Endoscopic Detection of Vocal Fold Scarring Using Dynamic Optical Contrast Imaging

Introduction: Accurate, noninvasive detection of vocal fold scarring remains a significant clinical challenge. We evaluate an endoscopic application of Dynamic Optical Contrast Imaging (DOCI) in a rabbit model of unilateral VF cordectomy.

Methods: An endoscopic DOCI system was subsequently employed to assess VF tissue in situ in a subset of animals following euthanasia . In this longitudinal study,  10 rabbits underwent endoscopic DOCI imaging of both VF. Nine of them then had immediate unilateral VF cordectomy; one was kept as an uninjured control to assess imaging stability over time. All 10 had serial in vivo endoscopic DOCI imaging at 2, 4, and 8 weeks during scar maturation. At the final time point, VF tissue was excised for ex vivo DOCI imaging and direct comparison with corresponding pentachrome histology

Results: Ex vivo DOCI imaging had reliably distinguished healthy from chronically scarred VF tissue, with the highest discriminative performance observed at 440–460 nm excitation (p < 0.05) while normal VF was unchanged over time. Endoscopic adaptation of DOCI did not achieve statistical significance at the 440–460 nm bandpass (corresponding to peak collagen emission), likely due to limitations introduced by endoscopic optical constraints, reduced excitation light delivery, and signal-to-noise challenges. Despite these limitations, endoscopic DOCI detected subtle longitudinal changes during scar maturation, with the injured VF demonstrating progressively increased fluorescence lifetime across 0, 2, 4, and 8 weeks, consistent with trends observed in ex vivo DOCI slide imaging.

Conclusions: These findings support the feasibility of DOCI as a clinically relevant endoscopic imaging modality for noninvasive, real-time identification of VF scarring. With further engineering refinement, DOCI has the potential to achieve diagnostic performance comparable to histology, improve clinical decision-making for ENT providers, guide management of VF pathology, and reduce reliance on invasive biopsy at the point of care.