Laser irradiation of biological tissue through water as a means of reducing thermal damage

Background and Objective: Reduction of thermal damage inbred with laser surgery is an ongoing challenge. The cavitation effect has been shown to facilitate the transmission of a laser beam through the otherwise opaque water layer. We suggest that by immersing the target tissue in water during laser surgery, thermal damage will be diminished. Study Design/Materials and Methods: A method of irradiating tissue by CO2 laser through a layer of a few millimeters of water is described. A series of experiments was conducted on fresh bovine cornea immersed in water or in air, histology of thermal damage was compared. Results: We were able to show that irradiation of tissue immersed in water reduces the thermal damage caused to the area surrounding the incision as compared to the damage caused during irradiation of tissue in air (P < 0.001). Conclusion: Laser surgery of tissue immersed in water can reduce the inbred thermal damage. Application of this method to clinical use may result in precise, clean cutting, and enable the use of CO2 laser through water. (C) 1996 Wiley-Liss, Inc.