Laser applications in clinical medicine

Laser energy sources have been used in a wide range of clinical applications over the last decade to obtain cutting, coagulation, and denaturization of tissue. The therapeutic effect depends on complex interaction among the optical and thermal properties of tissue and damage accumulation. In applications where localized white coagulum is required, there are trade-offs between continuous activation using a large spot size and repetitive pulses with a small spot size as well as between a highly scattered, deep penetration source and a highly absorbed, shallow penetration laser source. For applications involving ablation of tissue, high intensity, pulsed, shallow penetration sources have many advantages over continuously activated penetrating sources. In this article, the range of applications is reviewed with particular attention to the underlying physical phenomena that influence the choice of treatment parameters.