CO2 Laser Photothermal Effects on Rats Skin Tissues

Abstract

Spectroscopic and histological study of CO₂ laser interaction with rats tissues were carried out. We detected for the first time the changes in optical absorption spectra of rat's tissues with selective CO₂ laser optical densities ranging from 20.64 to 34.40W/cm². The laser exposed tissues show higher absorbance in hemoglobin than that for the unexposed tissue. Using the same laser and same optical densities, the absorption spectra of fresh blood were measured. Much intense peaks of hemoglobin than that for the corresponding peaks for the tissue were detected. A scheme based on recent experimental findings is proposed for explanation of this novel phenomenon. The histological study shows thermal damage of blood vessels localized at the dermis layer. At high laser optical densities a vessel rupture with hemorrhage were occurred. The results indicate a pronounced modification of skin absorption properties by laser irradiation. Such an effect is due to thermally induced biophysical and biochemical processes inside the highly heterogeneous tissue structure.

Keywords: CO₂ laser, Photothermal effects, Hemoglobin absorption, Histology