Prognostic Fluorescence lifetime measurements with DOCI

Scar formation in tissue is a healing process that inhibits normal tissue function through the deposition of predominantly disorganized type I collagen which is much more rigid than native collagen. Scarring in the vocal fold is especially debilitating as the vocal fold requires flexibility and freedom of movement to produce voicing. Furthermore the vocal fold has a very layered and organized structure with type I collagen in the basement membrane providing organ structural support, while type III collagen is in high concentration in the deep layer of the vocal fold. Using Dynamic Optical Contrast Imaging (DOCI) on unstained histological rabbit vocal fold slides (formalin fixed paraffin embedded tissue, FFPE), we were able to use subtle differences in fluorescence lifetime between native and scarred collagen types to image molecular evolution of scarring following injury. The degree of scarring and the DOCI fluorescence life time shift correlated with molecular and functional evaluations of scarring. Preliminary results demonstrates DOCI could be used as a prognostic tool useful to clinicians by depicting scar damage on vocal folds, (VF) not visible to the unaided eye or with white light endoscopic imaging.