ABSTRACT
In order to investigate the safety and efficacy of low energy laser irradiation to the arthritis of the patients with rheumatoid arthrtis, a multi-center double blind comparative study was conducted.<br>Sixty eight patients with rheumatoid arthritis were randomly allocated into two groups of laser and sham irradiation. The each inflamed knee joint received 3 minut's irradiation of Ga-AI-As laser at 20mw with wave length of 830nm or 3 minut's sham irradiation, twice a week during 5 weeks. Evaluation items included pain and swelling of the knee joint, 15m walking time, ESR and morning stiffness. Routine laboratory tests including CBC, blood chemistry such as GOT, GPT, and LDH were also examined at the entry of the study and the completion of 10 times irradiation. Among various evaluation items, 15m walking time showed significant decrease in the laser group comparing with that in the sham group (P<0.01). The remaining items showed no significant differences between two groups. Laboratory data showed no remarkable changes during the study and no apparent adverse effect with irradiation was observed.<br>These results show some beneficial effect of low energy laser therapy to the patient with rheumatoid arthritis and also safety of irradiation.