Therapeutic applications of polarized light: Tissue healing and immunomodulatory effects

As the population grows and ages, non-pharmaceutical options for the treatment and management of wounds, disease and injury are required to ensure adequate care. Polarized light therapy (PLT) utilizes visible-spectrum polarized light for a number of clinical applications. The advantage of polarized light is that it is able to penetrate the skin to a depth of up to 5 cm, reaching deeper tissues involved in wound healing. PLT has been shown to accelerate the healing process for ulcers, surgical wounds and dermal burns as well as a small number of musculoskeletal injuries. As research into the histological and physiological effects of PLT is largely absent, studies related to other light therapy modalities, largely low-level laser therapy, may pave the way to identify putative mechanisms by which PLT might exert its effects. Changes to cell signalling and secretion of substances required for wound healing have been identified in response to phototherapies. The reviewed literature suggests that PLT may be efficacious in some wound and injury healing contexts, though a gap in the literature exists regarding its mechanisms of action. Future studies should fully explain the therapeutic effects of PLT and the physiological mechanisms underpinning them.