ABSTRACT
In the 1980s, Anderson and Parish introduced the theory o f selective photothermolysis, revolutionizing cutaneous laser surgery. Selective photothermolysis occurs when a laser fight wavelength reaches a specific target and is preferentially ab sorbed, thereby minimizing unwanted thermal injury. For this to occur, there must be selective fight absorption and a short enough laser delivery time so that heat conduc tion is minimal. The duration o f laser delivery must be shorter than the thermal relax ation time (TRT) of the target. TRT is the time needed for a given heated tissue structure to lose half its heat. Table 71.2 fists the TRT for common targets. The energy density, or fluence, supplied by the laser must also be satisfactory to attain the desired response of the target within the allotted time for selective photothermolysis to occur.
quasi-CW, and pulsed device lasers. CW mode lasers (e.g., C 0 2 or older argon
