Light Therapy and MRI Imaging for Knee Osteoarthritis Pain

Managing joint pain is one of the main goals for treating osteoarthritis (OA) and other musculoskeletal disorders. Alleviating chronic pain pharmacologically has several potential drawbacks including diminishing efficacy, toxicity, adverse side-effects, and patient anxiety. Non-pharmacological approaches (eg. weight loss) have also been found to be effective at controlling joint pain and can provide supplementary benefits. The development of efficacious, alternative treatments for arthritis pain which provide analgesia without adverse side-effects would be advantageous. Recently, preclinical and clinical studies have demonstrated that green ambient light using light-emitting diodes (LEDs) produced profound analgesia in animal models and chronic pain patients. Both migraineurs and fibromyalgia patients have both reported significant reductions in pain following 10 weeks of green LED exposure. It is unknown how green light reduces pain, but it is believed to be in the connections between the visual and pain control centres in the brain. Investigators will examine whether green light reduces OA knee pain by altering pain processes in the brain. To assess this, we will recruit 44 participants and randomly assign them to one of two groups: one group will receive light treatments every day for 20 weeks and the other group will not. We will ask both groups to report pain in daily pain diaries and ask both groups to have a series of 3 MRI brain scans to determine if light exposure changes how the brain processes pain.