Effect of Visible Light Therapy in Patients with Somatic Pain

ABSTRACT

OBJECTIVE: The purpose of this study is to evaluate the effect of visible light therapy for the management of somatic pain. METHOD: Subjects consisted of 42 patients with pain and were divided into two groups; control (n=22) and experimental (n=20) groups. Control group received conventional physical therapy only, while experimental group received additional light therapy with blue light (light intensity 4080 lux, wave length 581 nm, distance from lamp 5 cm). Intensity of pain was assessed by visual analogue scale (VAS) and McGill pain questionnaire. Sympathetic skin response was measured to assess the status of autonomic nervous system. VAS and McGill pain questionnaire were administered before treatment and at 1 day, 2 days, 3 days, 1 week, and 2 weeks after treatment. Sympathetic skin response were performed before and 2 weeks aftertreatment. RESULTS: 1) In both experimental and control groups, VAS became significantly lower at two weeks after treatment compared to pretreatment scale (p<0.05). 2) McGill pain questionnaire showed significantly lower scores two weeks after treatment compared to pretreatment score, only in experimental group (p<0.05). 3) Experimental group showed significantly lower McGill pain questionnaire score than control group at two weeks after treatment (p<0.05). 4) Latency and amplitude of sympathetic skin response showed no significant difference between experimental and control groups. CONCLUSION: Visible light therapy can be used as an effective therapeutic modality for the management of symptomatic pain in combination with conventional physical therapy.