Many biomedical applications of lasers have been developed. In many cases, however, selection of a particular laser has been based largely on availability, and treatment protocols have often been developed by an empirical approach. Selective photothermolysis (SP) has been proposed as a construct which may be useful in designing laser systems for biomedical applications, especially for the treatment of pigmentary dermatoses. The necessary conditions are (1) tissue structures which preferentially absorb a wavelength of light more than the surrounding tissue, (2) a pulse of light sufficiently short and energetic to produce localized high temperatures in the absorbing structures, and (3) a predominantly thermal mode of initiation of tissue damage. The concept of selective photothermolysis was confirmed by our experimental observations. The lasers, with a pulse of light sufficiently short and energetic to produce localized high temperatures in the targets, were demonstrated to be useful for treatment of some pigmented and vascular lesions which showed no significant response to previous therapies. Furthermore, SP of hair follicles can also be applied for removal of excess hair growth in unwanted areas. Photoablation by using CO2 or excimer lasers is used for microsurgery of the skin, especially skin resurfacing.
Nippon Laser Igakkaishi 19 (4), 249-258, 1998
Japan Society for Laser Surgery and Medicine