Low level laser therapy also known as transcranial photobiomodulation therapy is a modality using low power lasers and light-emitting diodes in the far-red to near-infrared optical region to penetrate brain tissues and enhance ATP biosynthesis, regulate mitochondrial homeostasis, enhance serotonin and dopamine levels in the brain and facilitate neurogenesis and/or neuroplasticity proposed for the treatment of depression and Alzheimer’s disease. Preliminary clinical study evidence explores the potential use of low level laser therapy for major depressive disorder; however, future studies are needed to clarify ideal stimulation parameters and the overall efficacy, effectiveness and safety of this treatment. The evidence is insufficient to determine the effects of the technology on health outcome.
The evidence for low-level laser therapy in individuals who have increased risk of oral mucositis due to some cancer treatments (e.g., chemotherapy, radiotherapy) and/or hematopoietic stem cell transplantation includes randomized controlled trials (RCTs) and systematic reviews of RCTs. Relevant outcomes are symptoms, morbid events, quality of life, and treatment-related morbidity. Studies included patients undergoing various cancer chemotherapy regimens or hematopoietic stem cell transplantation. A recent systematic review of RCTs on low-level laser for prevention of oral mucositis included 18 RCTs, generally considered at low risk of bias, and found statistically significantly better outcomes with low-level laser therapy than control conditions on primary and secondary outcomes. In addition, three double-blind RCTs published in 2015 found significantly better outcomes in individuals undergoing low-level laser therapy than undergoing sham treatment prior to or during cancer treatment. The evidence is sufficient to determine qualitatively that the technology results in a meaningful improvement in the net health outcome.
In 2020, Peng et al. performed a meta-analysis involving 30 studies comparing prophylactic and therapeutic low level laser therapy (LLLT) to placebo or no therapy in reducing the risk of severe oral mucositis (OM) in individuals receiving chemotherapy or radiotherapy. The authors determined prophylactic and therapeutic low level laser therapy can reduce the risk of severe oral mucositis in individuals receiving chemotherapy or radiotherapy.
In an experimental, prospective double-blind randomized controlled study in 2019, Marin-Conde et al. conducted amongst 26 individuals diagnosed with oral squamous cell carcinoma undergoing oncological treatment. The objective of the study was to assess the effectiveness of photobiomodulation with low level laser therapy (LLLT) as a preventive and therapeutic procedure for the treatment of oral and oral pharyngeal mucositis caused by radio-chemotherapy in individuals diagnosed with oral squamous cell carcinoma. The study showed photobiomodulation with LLLT reduced the incidence and severity of mucositis in individuals treated with radiotherapy and chemotherapy.
The evidence for low-level laser therapy in individuals who have orthopedic pain (i.e., neck pain, osteoarthritis knee pain, low back pain, carpal tunnel syndrome) includes RCTs and, for some indications, systematic reviews of RCTs. Relevant outcomes are symptoms, functional outcomes, quality of life, and treatment-related morbidity. Findings of the RCTs were mixed and had methodologic limitations. The evidence is insufficient to determine the effects of the technology on health outcome.
In 2020, Martimbiano et al. performed a meta-analysis
to determine the benefits and harms of low level laser therapy for achilles
tendonopathy. Four trials involving 119 individuals were analyzed.The certainty
of evidence was low to very low, low, and the results were insufficient to
support the routine use of laser therapy for achilles tendonopathy.
The evidence for low-level laser therapy in individuals who have shoulder conditions, heel pain, or temporomandibular joint pain includes RCTs and, for some indications, systematic reviews of RCTs. Relevant outcomes are symptoms, functional outcomes, quality of life, and treatment-related morbidity. Findings of the RCTs were mixed and had methodologic limitations. The evidence is insufficient to determine the effects of the technology on health outcome.
The evidence for low-level laser therapy in individuals who have bone, ligament, and joint conditions (e.g., rheumatoid arthritis, fibromyalgia) includes RCTs and, for some indications, systematic reviews of RCTs. Relevant outcomes are symptoms, functional outcomes, quality of life, and treatment-related morbidity. Findings of the RCTs were mixed and had methodologic limitations. The evidence is insufficient to determine the effects of the technology on health outcome.
The evidence for low-level laser therapy in individuals who have Bell's palsy includes an RCT. Relevant outcomes are change in disease status, functional outcomes, quality of life, and treatment-related morbidity. Bell's palsy may completely resolve within months and, thus, it is difficult to determine improvements from laser therapy over the natural resolution of the illness. The available RCT did not include a sham treatment; low-level laser therapy was superior to exercise only in this study. Sham-controlled studies are needed as well as additional studies comparing low-level laser therapy with alternative Bell's palsy treatments. The evidence is insufficient to determine the effects of the technology on health outcome.
The evidence for low-level laser therapy in individuals who have lymphedema includes RCTs, observational studies, and systematic reviews. Relevant outcomes are symptoms, functional outcomes, quality of life, and treatment related morbidity. Systematic reviews of RCTs and observational studies found methodologic flaws in the available studies and have not consistently found better outcomes in individuals receiving low-level laser therapy than in individuals receiving a control condition treatment. The evidence is insufficient to determine the effects of the technology on health outcome.
The evidence for low-level laser therapy in individuals who have chronic wounds includes RCTs and systematic reviews. Relevant outcomes are symptoms, change in disease status, and treatment-related morbidity. The few existing RCTs tend to have small sample sizes and risk of bias. The evidence is insufficient to determine the effects of the technology on health outcome.