POOR PENETRATION OF INFRARED AND HELIUM-NEON LOW-POWER LASER-LIGHT INTO THE DERMAL TISSUE

The skin transmittance for low power laser light was studied in vitro. The penetration of both He-Ne and infra-red lasers was observed for o nly a few millimeters. The most important absorption was observed at t he depth level of 0.4 and 0.5 mm. These results suggested that the der mal vascular plexus barrier seemed to decrease the penetration at that level. This finding should mean that the laser therapy did not have r eally direct effects on the deep tissues. However, the effects can be mediated by many different pathways.