Open Access
29 November 2018 Laser-induced tissue remodeling within the tympanic membrane
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Abstract
The tympanic membrane (TM) separates the outer ear from the tympanic cavity. Repeated pathologies can permanently decrease its tension, inducing conductive hearing loss and adhesive processes up to cholesteatoma. The current main therapy is its surgical reconstruction. Even though lasers have been proposed to tighten atrophic TMs, details of this effect, specifically histological analyses, are missing. We therefore used laser pulses to induce TM collagen remodeling in an animal model to compare the histological and electrophysiological effects of different applied laser intensities before entering clinical studies. We irradiated Fuchsin-stained areas of the TM in anesthetized mice with 532-nm laser-pulses of 10 mW for 30 s (0.3 J), 25 mW for 30 s (0.75 J) or 50 mW for 30 s (1.5 J) monitoring hearing with auditory brainstem responses (ABRs). The mice were sacrificed after 2 to 8 weeks and histologically analyzed. An increase in the TM thickness within the defined, stained, and irradiated areas could be observed after 4 weeks. Polarized light microscopy and transmission electron microscopy demonstrated the tissue volume increase majorly due to new collagen-fibrils. Directly after irradiation, ABR thresholds did not increase. We herein demonstrate a controlled laser-induced collagen remodeling within defined areas of the TM. This method might be the prophylactic solution for chronic inflammatory ear pathologies related to decreased TM tension.
CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Sophie A. L. Schacht, Patricia Stahn, Marius Hinsberger, Bernhard Schick, and Gentiana I. Wenzel M.D. "Laser-induced tissue remodeling within the tympanic membrane," Journal of Biomedical Optics 23(12), 121614 (29 November 2018). https://doi.org/10.1117/1.JBO.23.12.121614
Received: 27 June 2018; Accepted: 19 October 2018; Published: 29 November 2018
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CITATIONS
Cited by 7 scholarly publications.
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KEYWORDS
Collagen

Ear

Birefringence

Laser tissue interaction

Transmission electron microscopy

Microscopy

Laser irradiation

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