Effectiveness of laser photobiomodulation in the management of trigeminal neuralgia: a systematic review and meta-analysis

This systematic literature review aimed to assess the effectiveness of laser photobiomodulation therapy (PBM) in reducing pain in patients with trigeminal neuralgia and postherpetic neuralgia. Randomized controlled clinical trials were identified through searches in the following databases: PubMed, Web of Science, LILACS, EMBASE, Scopus, and the Cochrane Library. No studies involving patients with postherpetic neuralgia met the inclusion criteria and were therefore excluded. Nine studies, comprising a total of 387 patients diagnosed with trigeminal neuralgia, were included. In seven of these studies, patients also received pharmacological treatment, which was initiated either prior to or concurrently with the PBM intervention. A sham laser was used as a control in six studies. PBM parameters varied widely and were often incompletely reported, limiting the ability to compare treatment protocols. Qualitative analysis showed that eight out of nine studies reported a significantly greater reduction in pain scores in the PBM groups compared to control groups. A low to moderate risk of bias was found in two-thirds of the studies. The meta-analysis, which included five studies, demonstrated a significant effect of PBM in reducing pain scores (MD − 2.17; 95% CI, − 3.30 to − 1.04; P = 0.0002), although high heterogeneity was observed (I² = 92%). PBM appears to be an effective adjuvant therapy for trigeminal neuralgia, with a favorable safety profile and potential to reduce medication dependency. Nevertheless, the results should be interpreted cautiously due to substantial heterogeneity, lack of PBM protocol standardization, and limited long-term outcome data.