O efeito térmicos da fototerapia com a combinação de diferentes fontes de luz na pele humana

Abstract

The first reports on the application of phototherapy describing its mechanism of action secondary to increased temperature, although some authors maintain its heatless effect, however, the thermal effects in dark skin were observed when irradiated with Laser of 810nm and 904nm, with higher doses than those recommended by the World Association of laser therapy (WALT). However, super-pulsed irradiation emits relatively short pulses, limiting the thermal energy in the tissues, reduce thermal damage in normal tissue side. The aim of this study is to evaluate the thermal effect caused on human skin after irradiation with phototherapy equipment that combines red, infrared LED radiation and super- pulsed laser. It was included in the study 42 healthy subjects, above 18 years of age, both genders, different skin colors. The skin temperature was measured through the thermographic camera for the last 5 seconds of each dose of irradiation and will continue for 1 minute after the end of each irradiation. Irradiation was performed with the using a multi-diode cluster of phototherapy with four 905 nm super-pulsed diodes with frequency of 250 Hz, four 875 nm LED diodes, and four 640 nm LED diodes (manufactured by Multi Radiance MedicalTM, Solon – OH, USA). The following doses was tested: placebo - 0 J (60 seconds), 10 J (76 seconds), 30 J (228 seconds), 50 J (380 seconds). None of doses tested lead to significant increases of temperature regarding different skin color groups (p>0.05), age groups (p>0.05), and neither gender groups (p>0.05). Our results shows that combination of super-pulsed laser, red and infrared LEDs is safe and can be used in any kind of patient since there aren't damaging thermal effects. Since doses used in this study previously positive effects in clinical trials using the same device, we can conclude also that combination of super-pulsed laser, red and infrared LEDs lead to positive effects in clinical settings without thermal effects, which illustrates the desirable photobiomodulatory effect.