“Helium-neon laser radiation had a statistically significant stimulating effect on collagen synthesis in the wound, with a maximum effect at an energy density of 4 joules/sq cm. The rate of wound closure was enhanced significantly between the third and 12th postoperative days. The argon laser exposure produced a significant increase in collagen concentration both in irradiated and nonirradiated contralateral wounds. However, an acceleration of the healing rate was not registered in this case.”

“The wound contraction up to the fourth day of the experiment was inhibited under helium-neon and argon laser exposure to 20 joules/sq cm. ”

The described effects were not specific for the laser light. There may be a wavelength-selective influence of coherent light on the metabolic and proliferation processes in wound healing, with the associated problem of the possible carcinogenic effects of laser radiation.”

“There was no qualitative difference in the effect on wound healing between the incoherent light and the laser of the same wavelength.”

“Rather, it indicates that the enhanced closure rate under helium-neon and incoherent red light exposure was caused by accelerated epithelization of the wound. An activation of epidermis cells has been observed histologically after nondestructive laser irradiation.”

Comment: Pal Greguss (1984) said that Kana didn’t observe any wound healing. Therefore, I think the full text should be carefully investigate to understand the contradiction.