Laser therapy, photobiomodulation - research information

Information about laser therapy research, photobiomodulation

Since laser therapy (LLLT, biostimulation, photobiomodulation) is still "new" for many practitioners and is somehow "complementary", we provide below a collection of international laser research (abstracts, studies). The collection is not complete and only a small part of the research. We would be pleased to send you further information.

→ FAQ (Frequently asked questions about laser therapy)

Regarding the mechanism of action of laser therapy, we recommend, among others, the research/articles of

  • Tina Karu "Cellular Mechanism of Low Power Laser Therapy" 
  • K. Walter "Photobiological basics"
  • Herbert Klima "Biophysical Aspects of Low Power Laser therapy"
  • M. Schaffer, H. Bonel, R. Sroka, M. Reiser "Untersuchung zum Nachweis der laserinduzierten Biomodulation mittels NMR", Klinikum Großhadern, Ludwig-Maximilians-Universität München
  • Prof. Dipl.-Ing. Dr.techn. Gerhard Litscher, Universitätsklinik für Anästhesiologie und Intensivmedizin, This email address is being protected from spambots. You need JavaScript enabled to view it., Researcher ID: A-5527-2012

Meta-analysis laser therapy for knee osteoarthritis, neck pain

Please contact RJ-LASER if you want the complete study

BMJ Open. 2019; 9(10): e031142.   Published online 2019 Oct 28. doi: 10.1136/bmjopen-2019-031142, PMCID: PMC6830679   PMID: 31662383

Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials

Martin Bjørn Stausholm,1 Ingvill Fjell Naterstad, Msc,1 Jon Joensen,1 Rodrigo Álvaro Brandão Lopes-Martins,2 Humaira Sæbø, Msc,1 Hans Lund,3 Kjartan Vibe Fersum,1 and Jan Magnus Bjordal1

Low-level laser therapy (LLLT) is not recommended in major knee osteoarthritis (KOA) treatment guidelines. We investigated whether a LLLT dose–response relationship exists in KOA.

Systematic review and meta-analysis.

Data sources
Eligible articles were identified through PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, Physiotherapy Evidence Database and Cochrane Central Register of Controlled Trials on 18 February 2019, reference lists, a book, citations and experts in the field.
Eligibility criteria for selecting studies:
We solely included randomised placebo-controlled trials involving participants with KOA according to the American College of Rheumatology and/or Kellgren/Lawrence criteria, in which LLLT was applied to participants’ knee(s). There were no language restrictions.
Data extraction and synthesis
The included trials were synthesized with random effects meta-analyses and sub-grouped by dose using the World Association for Laser Therapy treatment recommendations. Cochrane’s risk-of-bias tool was used.
22 trials (n=1063) were meta-analyzed. Risk of bias was insignificant. Overall, pain was significantly reduced by LLLT compared with placebo at the end of therapy (14.23 mm Visual Analogue Scale (VAS; 95% CI 7.31 to 21.14)) and during follow-ups 1–12 weeks later (15.92 mm VAS (95% CI 6.47 to 25.37)). The subgroup analysis revealed that pain was significantly reduced by the recommended LLLT doses compared with placebo at the end of therapy (18.71 mm (95% CI 9.42 to 27.99)) and during follow-ups 2–12 weeks after the end of therapy (23.23 mm VAS (95% CI 10.60 to 35.86)). The pain reduction from the recommended LLLT doses peaked during follow-ups 2–4 weeks after the end of therapy (31.87 mm VAS significantly beyond placebo (95% CI 18.18 to 45.56)). Disability was also statistically significantly reduced by LLLT. No adverse events were reported.
LLLT reduces pain and disability in KOA at 4–8 J with 785–860 nm wavelength and at 1–3 J with 904 nm wavelength per treatment spot.

Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomized placebo or active-treatment controlled trials

Roberta T Chow, Mark I Johnson, Rodrigo A B Lopes-Martins, Jan M Bjordal

Background Neck pain is a common and costly condition for which pharmacological management has limited evidence of efficacy and side-effects. Low-level laser therapy (LLLT) is a relatively uncommon, non-invasive treatment for neck pain, in which non-thermal laser irradiation is applied to sites of pain. We did a systematic review and meta-analysis of randomised controlled trials to assess the efficacy of LLLT in neck pain.
Methods: We searched computerized databases comparing efficacy of LLLT using any wavelength with placebo or with active control in acute or chronic neck pain. Effect size for the primary outcome, pain intensity, was defined as a pooled estimate of mean difference in change in mm on 100 mm visual analogue scale.
Findings: We identified 16 randomized controlled trials including a total of 820 patients. In acute neck pain, results of two trials showed a relative risk (RR) of 1·69 (95% CI 1·22–2·33) for pain improvement of LLLT versus placebo. Five trials of chronic neck pain reporting categorical data showed an RR for pain improvement of 4·05 (2·74–5·98) of LLLT. Patients in 11 trials reporting changes in visual analogue scale had pain intensity reduced by 19·86 mm (10·04–29·68). Seven trials provided follow-up data for 1–22 weeks after completion of treatment, with short-term pain relief persisting in the medium term with a reduction of 22·07 mm (17·42–26·72). Side-effects from LLLT were mild and not different from those of placebo.
Interpretation: We show that LLLT reduces pain immediately after treatment in acute neck pain and up to 22 weeks after completion of treatment in patients with chronic neck pain.