Nd:YAG laser modulation of synovial tissue metabolism.

In studies designed to establish the safety and efficacy of laser treatment of arthritis, the in vitro effect of Nd:YAG laser radiation on normal, osteoarthritic and rheumatoid synovial tissue and synovial fibroblast metabolism has been addressed. Defined energy levels of normal pulsed radiation (TEMoo mode) consistently up-regulated synovial tissue explant culture hyaluronic acid and protein synthesis. In contrast, high intensity Q-switched delivery down-regulated the response. The application of normal pulsed radiation had a variable effect on synovial fibroblast synthesis but the response of any given cell isolate was consistent. DNA synthesis and cell viability were not affected.