Do Patients With Carpal Tunnel Syndrome Benefit From Low-Level Laser Therapy? A Systematic Review of Randomized Controlled Trials

Objective: To systematically review the literature on the effectiveness of low-level laser therapy for patients with carpal tunnel syndrome. Data Sources: The Cochrane Library, PubMed, Embase, CINAHL, and Physiotherapy Evidence Database were searched for relevant systematic reviews and randomized controlled trials (RCTs) up to April 8, 2016. Study Selection: Two reviewers independently applied the inclusion criteria to select potential studies. Data Extraction: Two reviewers independently extracted the data and assessed the methodologic quality. Data Synthesis: A best-evidence synthesis was performed to summarize the results of the 2 systematic reviews and 17 RCTs that were included. Strong evidence was found for the effectiveness of low-level laser therapy compared with placebo treatment in the very short term (0 to ≤5wk). After 5 weeks, the positive effects of low-level laser therapy on pain, function, or recovery diminished over time (moderate and conflicting evidence were found at 7- and 12-wk follow-up, respectively). Conclusions: In the very short term, low-level laser therapy is more effective as a single intervention than placebo low-level laser therapy in patients with carpal tunnel syndrome, after which the positive effects of low-level laser therapy tend to subside. Evidence in the midterm and long term is sparse.