Collagen denaturation can be quantified in burned human skin using polarization-sensitive optical coherence tomography

Quantifiable prognostic indicators are of considerable practical value following thermal injury. Collagen is a major component of the skin, and is known to undergo denaturation at the elevated temperatures associated with burns. The purpose of this study was to determine whether a recently developed, non-invasive imaging technique could detect and quantify collagen denaturation in burned human skin. Polarization-sensitive optical coherence tomography (PS-OCT) imaging was used to quantify collagen birefringence in normal human skin, and in skin excised from burn patients. Images were acquired and displayed in 1 s, and demonstrated qualitative differences between normal and partial-thickness burned human skin. Birefringence loss due to thermal denaturation of collagen was quantified, with mean phase retardation rates for samples of 26 normal and 26 burned skin sites determined to be 0.401±0.020 and 0.249±0.017°/μm, respectively (mean±S.E.M.), with this difference in sample means shown to be statistically significant (P<0.000001). Analysis of the accuracy of the technique indicated that PS-OCT measurements may be made with resolution sufficient to distinguish between burns of varying severity. In conclusion, PS-OCT is capable of imaging and quantifying collagen denaturation in burned human skin, providing a new parameter against which post-injury outcome may be compared.