Collagen Content Limits Optical Coherence Tomography Image Depth in Porcine Vocal Fold Tissue.
OBJECTIVE
Vocal fold scarring, a condition defined by increased collagen content, is challenging to treat without a method of noninvasively assessing vocal fold structure in vivo. The goal of this study was to observe the effects of vocal fold collagen content on optical coherence tomography imaging to develop a quantifiable marker of disease.


STUDY DESIGN
Excised specimen study.


SETTING
Massachusetts Eye and Ear Infirmary.


SUBJECTS AND METHODS
Porcine vocal folds were injected with collagenase to remove collagen from the lamina propria. Optical coherence tomography imaging was performed preinjection and at 0, 45, 90, and 180 minutes postinjection. Mean pixel intensity (or image brightness) was extracted from images of collagenase- and control-treated hemilarynges. Texture analysis of the lamina propria at each injection site was performed to extract image contrast. Two-factor repeated measure analysis of variance and t tests were used to determine statistical significance. Picrosirius red staining was performed to confirm collagenase activity.


RESULTS
Mean pixel intensity was higher at injection sites of collagenase-treated vocal folds than control vocal folds (P < .0001). Fold change in image contrast was significantly increased in collagenase-treated vocal folds than control vocal folds (P = .002). Picrosirius red staining in control specimens revealed collagen fibrils most prominent in the subepithelium and above the thyroarytenoid muscle. Specimens treated with collagenase exhibited a loss of these structures.


CONCLUSION
Collagen removal from vocal fold tissue increases image brightness of underlying structures. This inverse relationship may be useful in treating vocal fold scarring in patients.
['Garcia|Jordan A|JA|', 'Benboujja|Fouzi|F|', 'Beaudette|Kathy|K|', 'Rogers|Derek|D|', 'Maurer|Rie|R|', 'Boudoux|Caroline|C|', 'Hartnick|Christopher J|CJ|']
D000818:Animals D002921:Cicatrix D003094:Collagen D004195:Disease Models, Animal D066298:In Vitro Techniques D013552:Swine D041623:Tomography, Optical Coherence D014827:Vocal Cords
collagen optical coherence tomography vocal fold scarring