Abstract

The infrared laser beam employed as a Low Level Laser Therapy (LLLT) is postulated by many authors as pain reliever and scar tissue healing by increasing cellular metabolism, irrigation and tisular cells repairing. The main goal of this experience was to check the thickness of healthy rabbit isquiatic perineurium nerve, which were irradiated with infrared laser. In each session, ten healthy rabbits were irradiated on the skin of the rigth leg with 10 Joule/cm2 energy during 9 minutes to complete 10 of them, according to the rules of kinesic treatment. The animals were sacrified and their legs dissected, extracting the right and left isquiatic nerves. All nerves were treated by histologic procedure in order to observe collagen tissue (Van Giesson and Mallory methods). The left side nerve was used as a control. Perineurium thickness measurement was performed with a reticulated micrometer (400 X 0,25mm2) located at the ocular piece of the ligth microscope and both irradiated and control nerve histologic preparations, were observed. The results were subjected to statistical analysis using the SPSS for window 7.0 computational program. It was possible to verify that perineurium thickness is not quite exactly the same in all the fascicles, in both groups of nerves. Furthermore, the average perineurium thickness was 27.8 um for irradiated nerves and 21 um for control nerves, showing a statistically significant difference between them. In addition to this fact, the irradiated nerves showed bigger volumes and agreat amount of fat in comparison to control nerves. The conclusion is that application of infrared laser beam produces a variation in normal morphology of peripherical nerves.