Effects of Near Infrared Light on Surgical Wound Healing: A Systematic Review and Meta‐Analysis

Near infrared (NIR) therapy is increasingly used to enhance postoperative wound healing, yet clinical trial results remain inconsistent. To evaluate the effectiveness of NIR therapy on postoperative wound healing and identify treatment parameters associated with optimal outcomes: This systematic review and meta-analysis registered at PROSPERO (CRD420251163415) assessed evidence on comparing NIR therapy (630-1100 nm) with standard care or placebo on healing of surgical-induced wounds. A multilevel random-effects meta-analysis of standardised mean differences (SMDs) was conducted. Moderator analyses examined the wavelength, fluence, session number, application technique and anatomical site. Risk of bias was assessed using Cochrane RoB 2.0 and certainty of evidence was rated with GRADE. Fifty-six trials (N = 4920) were included for systematic review and 35 trials contributed 69 outcomes to meta-analysis. NIR significantly improved wound healing (0.78, [0.46-1.09], p < 0.01) and reduced postoperative pain (0.71, [0.24-1.17], p < 0.01), but heterogeneity was high and effects varied across studies. Optimal outcomes were associated with short NIR wavelengths (700-850 nm), 4-10 sessions and non-contact application. Effects on swelling, scarring and inflammatory markers were inconsistent. Overall, certainty of evidence was very low. This first systematic review and meta-analysis indicates that NIR therapy demonstrates promise for enhancing postoperative healing and reducing pain, though effects vary by protocols.