Revealing structural modifications in thermomechanical reshaping of collagenous tissues using optical coherence elastography.

Moderate heating of such collagenous tissues as cornea and cartilages by IR-laser irradiation is an emerging technology for non-destructive modification of the tissue shape and microstructure for a variety of applications in ophthalmology, otolaryngology, etc. Post-irradiation high-resolution microscopic examination indicates the appearance of microscopic either spheroidal or crack-like narrow pores depending on the tissue type and irradiation regime. Such examinations usually require special tissue preparation (e.g., staining, drying that affect microstructure themselves) and are mostly suitable for studying individual pores, whereas evaluation of their averaged parameters, especially in situ, is challenging. Here, we demonstrate OCT's ability to visualize areas of pore initiation and evaluate their averaged properties by combining visualization of residual irradiation-induced tissue dilatation and evaluation of the accompanying Young-modulus reduction by OCT-based compressional elastography. We show that the averaged OCT-based data obtained in situ fairly well agree with the microscopic examination results. The results obtained develop the basis for effective and safe applications of novel non-destructive laser technologies of tissue modification in clinical practice. This article is protected by copyright. All rights reserved.