Effects of Power Output and Energy Density on the Histologic Change of Guinea pig Skin Following Copper Vapor Laser Irradiation / 대한피부과학회지

ABSTRACT

BACKGROUND: Recentliy copper vapor laser(CVL) has been applied with encouraging results in the treatment of port wine stain. The CVL emits yellow light(578nm) in a sequence of about 10,000 to 15,000 pulses/second(10-15kHz) with a pulse duration of 15-50 cases. One of the basic methods of evaluationg the effects of laser lights is to study histologic changes after laser irradiation. OBJECTIVE: The effects of power output and energy density on the histologic change of guinea pig skin following CVL irradiation was evaluted to suggest a way of deciding parameters of CVL to achieve the best clinical results. METHODS: After setting the power output for one of 0.8W, 1.6W and 2.4W, the laser was irradiated with an energy density of 10, 12, 14, 16, 18, 20J/cm. A biopsy was done 15 minutes after irradiation and the biopsy specimens was stained with H&E and NBTC histocberr ical method. RESULTS: 1. At the power of 0.8W, specimens irradiated with an energy density above 14J/cm showed diffuse nonspecific coagulation necrosis of the epidermis and upper dermis. 2. At the power of 1.6W, specimens irradiated with energy density of 14, 16J/cm showed coagulation necrosis of dermal vessel and perivascular collagen. With energe density of 18, 20J/cm, diffuse nonspecific coagulat,ion necrosis of epidermis and upper dermis were observed. 3. At the power of 2.4W, specimens irradiated with an anergy density of 12, 14, 16, 18J/cm showed coagulation necrosis of the dermal vessel and perivascular collagen. With an energy density of 20J/cm, diffuse nonspecific coagulation necrosis of the epidermis and upper dermis was observed. CONCLUSIONS: With the above results it was found that t,he higher power output of CVL enlarged the range of energy density confining thermal damage to the dermal v-ssels and perivascular collagen. Additionally the higher power raised the upper limit of energy density with which t,he epidermis was viable.