A theoretical study of the effect of optical properties in laser ablation of tissue

The role of optical properties in the distribution of laser light and the resulting thermodynamical processes in biological tissue are studied from a theoretical perspective. Light distribution is modeled by a discrete ordinate method, and heat transfer and ablation are modeled by an immobilized finite-element method. The effect of parametric variation of absorption, scattering, and scattering anisotropicity on the dynamics of the ablation process is examined. The manifestation of temperature higher than the ablation threshold temperature in the subsurface tissue is observed and discussed. Results indicate significant differences in the ablation behavior, which may have important clinical implications.