Changes in optical properties of rat skin during thermal coagulation

Abstract

Thermal coagulation of albino rat skin heated in vitro results in prominent changes of light scattering but relatively little in light absorption based on measurements using an integrating sphere spectrometer. The reduced scattering coefficients, (mu) <SUB>s</SUB>(1-g), gradually increase as temperatures increase from room temperature to 55 degree(s)C then rapidly decrease to plateau after 70 degree(s)C is reached. The differences among the (mu) <SUB>s</SUB>(1-g) values for the different wavelengths were greater at the lower temperatures than at higher temperatures. The absorption coefficient, (mu) <SUB>a</SUB>, changed very little over the test temperature range (room temperature to 90 degree(s)C) and then only at higher temperatures and for longer wavelengths. The optical property changes were associated with thermally induced light microscopic and ultrastructural changes in the dermal collagen, a major tissue component of skin.