Low level laser therapy
|Low-level laser therapy|
Demonstration of LLLT
with intranasal irradiation
Low-level laser therapy (LLLT) is a form of alternative medicine that applies low-level (low-power) lasers or light-emitting diodes (LEDs) to the surface or orifices of the body. Whereas "high-power" lasers are used in laser medicine to cut or destroy tissue, low-power lasers are claimed to relieve pain or to stimulate and enhance cell function.
Despite a lack of consensus over its scientific validity, specific test and protocols for LLLT suggest it may be modestly effective, but in most cases no better than placebo, in relieving short-term pain for rheumatoid arthritis, osteoarthritis, acute and chronic neck pain, tendinopathy, and possibly chronic joint disorders. The evidence for LLLT being useful in the treatment of low back pain, dentistry and wound healing is unclear.
Variations of LLLT have gone by a variety of alternate names including low-power laser therapy (LPLT), soft laser therapy, low-intensity laser therapy, low-energy laser therapy, cold laser therapy, bio-stimulation laser therapy, photo-biotherapy, therapeutic laser, and monochromatic infrared light energy (MIRE) therapy. When LLLT is administered to so-called "acupuncture points", the procedure may be called laser acupuncture.
Various LLLT devices have been promoted for use in treatment of several musculoskeletal conditions including carpal tunnel syndrome (CTS), fibromyalgia, osteoarthritis, and rheumatoid arthritis. They have also been promoted for temporomandibular joint (TMJ) disorders, wound healing, smoking cessation, and tuberculosis. While they may briefly help some people with pain management, evidence does not support claims that they change long term outcomes, or that they work better than other, low tech ways of applying heat.
The Centers for Medicare and Medicaid Services, Aetna, and Cigna have reviewed the clinical evidence with respect to LLLT and found it insufficient to determine that LLLT is safe or effective for any purpose.
LLLT may be useful in the treatment of both acute and chronic neck pain. In neck pain the benefit was not of significant importance and the evidence had a high risk of bias. A 2008 Cochrane Library review concluded that LLLT has insufficient evidence for treatment of nonspecific low back pain, a finding echoed in a 2010 review of chronic low back pain. A 2015 review found benefit in nonspecific chronic low-back pain.
There is tentative data that LLLT is useful in the short-term treatment of pain caused by rheumatoid arthritis, and possibly chronic joint disorders. While it does not appear to improve pain in temporomandibular disorders, it may improve function. Evidence for useful in osteoarthritis is poor.
There is tentative evidence of benefit in tendinopathy. A 2015 review found benefit in shoulder tendinopathy. A 2014 Cochrane review found tentative evidence that it may help in frozen shoulders.
Similarly, the use of lasers to treat chronic periodontitis and to speed healing of infections around dental implants is suggested, but there is insufficient evidence to indicate a use superior to traditional practices.
A 2014 review found tentative evidence of benefit for lasers. While another 2014 review concluded that the results are mixed, have a high risk of bias, and that its effectiveness is unclear. A 2015 review also found tentative evidence of benefit.
Stephen Barrett, writing for Quackwatch, concluded in 2009 there was evidence to support LLLT use for temporary pain relief, but "there's no reason to believe that they will influence the course of any ailment or are more effective than other forms of heat delivery." Barrett's position was unchanged as of 2016.
It is unclear how LLLT might work.
Photochemical reactions are well known in biological research; it may be that the light applied in low level laser therapy might react with the respiratory enzyme cytochrome c oxidase which is involved in the electron transport chain in mitochondria.
Hungarian physician and surgeon Endre Mester (1903-1984) is credited with the discovery of the biological effects of low power lasers, which occurred a few years after the 1960 invention of the ruby laser and the 1961 invention of the helium–neon (HeNe) laser. Mester accidentally discovered that low-level ruby laser light could regrow hair during an attempt to replicate an experiment that showed that such lasers could reduce tumors in mice. The laser he was using was faulty and wasn't as powerful as he thought; it failed to affect the tumors but he noticed that in the places where he had shaved the mice in order to do the experiments, the hair grew back faster on mice he treated compared with the placebos. He published those results in 1967. He went on to show that low level HeNe light could accelerate wound healing in mice. By the 1970s he was applying low level laser light to treat people with skin ulcers. In 1974 he founded the Laser Research Center at the Semmelweis Medical University in Budapest, and continued working there for the remainder of his life. His sons carried on his work and brought it to the United States.
By 1987 companies selling lasers were claiming that they could treat pain, accelerate healing of sports injuries, and treat arthritis, but there was little evidence for this at that time. By 2016 they had been marketed for wound healing, smoking cessation, tuberculosis, and musculoskeletal conditions such as temporomandibular joint disorders carpal tunnel syndrome, fibromyalgia, osteoarthritis, and rheumatoid arthritis, and there was still little evidence for these uses, other than a possible use in temporarily treating muscle or joint pain.
Mester originally called this approach "laser biostimulation'", but it soon became known as “low level laser therapy" and with the adaptation of light emitting diodes by those studying this approach, it became known as "low level light therapy", and to resolve confusion around the exact meaning of "low level", the term "photobiomodulation" arose.
Society and culture
Veterinary clinics use cold laser devices to treat a wide variety of ailments, from arthritis to wounds, on dogs and cats. Very little research has been done on the effects of this treatment on animals. Currently, laser therapy equipment is aggressively marketed to veterinarians as a supposedly powerful therapeutic tool and revenue generator. Brennen McKenzie, president of the Evidence-Based Veterinary Medical Association, has stated that “research into cold laser in dogs and cats is sparse and generally low quality. Most studies are small and have minimal or uncertain controls for bias and error”.  While allowing that some studies show promising results, he reports that others do not. While believing that there is enough evidence to warrant further study, he concludes that there is not enough evidence to support routine clinical use of cold laser in animals.
If vets want to try this therapy, they have an obligation to be clear with client that the risks and benefits have not been established and that the treatment is essentially experimental. There is nothing wrong with using such a treatment given appropriate informed consent, but the aggressive marketing of laser equipment to vets as a profitable treatment is ethically questionable given the lack of good evidence that it is a truly safe and effective treatment for any condition. 
- Bjordal, J. M.; Lopes-Martins, R. A.; Joensen, J. .; Couppe, C. .; Ljunggren, A. E.; Stergioulas, A. .; Johnson, M. I. (2008). "A systematic review with procedural assessments and meta-analysis of Low Level Laser Therapy in lateral elbow tendinopathy (tennis elbow)". BMC Musculoskeletal Disorders. 9: 75. doi:10.1186/1471-2474-9-75. PMC . PMID 18510742.
- Bjordal, JM; Couppé, C; Chow, RT; Tunér, J; Ljunggren, EA (2003). "A systematic review of low level laser therapy with location-specific doses for pain from chronic joint disorders". The Australian journal of physiotherapy. 49 (2): 107–16. doi:10.1016/s0004-9514(14)60127-6. PMID 12775206.
- Brosseau, L.; Welch, V.; Wells, G. A.; de Bie, R.; Gam, A.; Harman, K.; Morin, M.; Shea, B.; Tugwell, P. (2005). "Low level laser therapy (Classes I, II and III) for treating rheumatoid arthritis". Cochrane Database of Systematic Reviews (4): CD002049. doi:10.1002/14651858.CD002049.pub2. PMID 16235295.
- Jamtvedt, G.; Dahm, K. T.; Christie, A.; Moe, R. H.; Haavardsholm, E.; Holm, I.; Hagen, K. B. (2007). "Physical Therapy Interventions for Patients with Osteoarthritis of the Knee: an Overview of Systematic Reviews". Physical Therapy. 88 (1): 123–136. doi:10.2522/ptj.20070043. PMID 17986496.
- Chow, R.; Johnson, M.; Lopes-Martins, R.; Bjordal, J. (Nov 2009). "Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomised placebo or active-treatment controlled trials.". Lancet. 374 (9705): 1897–1908. doi:10.1016/S0140-6736(09)61522-1. PMID 19913903.
- Tumilty, S. .; Munn, J. .; McDonough, S. .; Hurley, D. A.; Basford, J. R.; Baxter, G. D. (2010). "Low Level Laser Treatment of Tendinopathy: A Systematic Review with Meta-analysis". Photomedicine and Laser Surgery. 28 (1): 3–16. doi:10.1089/pho.2008.2470. PMID 19708800.
- Yousefi-Nooraie, R.; Schonstein, E.; Heidari, K.; Rashidian, A.; Pennick, V.; Akbari-Kamrani, M.; Irani, S.; Shakiba, B.; Mortaz Hejri, S.; Mortaz Hejri, S. O.; Jonaidi, A. (2008). Yousefi-Nooraie, Reza, ed. "Low level laser therapy for nonspecific low-back pain". Cochrane database of systematic reviews (Online) (2): CD005107. doi:10.1002/14651858.CD005107.pub4. PMID 18425909.
- Middelkoop, M.; Rubinstein, S. M.; Kuijpers, T.; Verhagen, A. P.; Ostelo, R.; Koes, B. W.; Van Tulder, M. W. (2010). "A systematic review on the effectiveness of physical and rehabilitation interventions for chronic non-specific low back pain". European Spine Journal. 20 (1): 19–39. doi:10.1007/s00586-010-1518-3. PMC . PMID 20640863.
- Cobb, C. M. (2006). "Lasers in Periodontics: A Review of the Literature". Journal of Periodontology. 77 (4): 545–564. doi:10.1902/jop.2006.050417. PMID 16584335.
- Sculean, A.; Schwarz, F.; Becker, J. (2005). "Anti-infective therapy with an Er:YAG laser: influence on peri-implant healing". Expert Review of Medical Devices. 2 (3): 267–76. doi:10.1586/174344188.8.131.527. PMID 16288590.
- Da Silva, J. P.; Da Silva, M. A.; Almeida, A. P. F.; Junior, I. L.; Matos, A. P. (2010). "Laser Therapy in the Tissue Repair Process: A Literature Review". Photomedicine and Laser Surgery. 28 (1): 17–21. doi:10.1089/pho.2008.2372. PMID 19764898.
- American Cancer Society. Cold Laser Therapy Page archived April 24, 2015
- Barrett, S (July 29, 2016). "A Skeptical Look at Low Level Laser Therapy". Quackwatch.
- "Decision memo for infrared therapy devices" (CAG00291N). Center for Medicare & Medicaid Services, Oct 24, 2006.
- "Infrared therapy". Aetna clinical policy bulletin 0604, reviewed Oct 23, 2014. Aetna has additional information in its "Clinical Policy Bulletin on Cold Laser and High-Power Laser Therapies".
- "CIGNA medical coverage policy: Low-level laser therapy". Revised, July 15, 2016.
- Kadhim-Saleh, Amjed; Maganti, Harinad; Ghert, Michelle; Singh, Sheila; Farrokhyar, Forough (2013-10-01). "Is low-level laser therapy in relieving neck pain effective? Systematic review and meta-analysis". Rheumatology International. 33 (10): 2493–2501. doi:10.1007/s00296-013-2742-z. ISSN 1437-160X. PMID 23579335.
his systematic review provides inconclusive evidence because of significant between-study heterogeneity and potential risk of bias.
- Huang, ZeYu; Ma, Jun; Chen, Jing; Shen, Bin; Pei, FuXing; Kraus, Virginia Byers (2015-01-01). "The effectiveness of low-level laser therapy for nonspecific chronic low back pain: a systematic review and meta-analysis". Arthritis Research & Therapy. 17: 360. doi:10.1186/s13075-015-0882-0. ISSN 1478-6362. PMC . PMID 26667480.
- Chen, J.; Huang, Z.; Ge, M.; Gao, M. (2015-04-01). "Efficacy of low-level laser therapy in the treatment of TMDs: a meta-analysis of 14 randomised controlled trials". Journal of Oral Rehabilitation. 42 (4): 291–299. doi:10.1111/joor.12258. ISSN 1365-2842. PMID 25491183.
- Huang, Z.; Chen, J.; Ma, J.; Shen, B.; Pei, F.; Kraus, V. B. (2015-09-01). "Effectiveness of low-level laser therapy in patients with knee osteoarthritis: a systematic review and meta-analysis". Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society. 23 (9): 1437–1444. doi:10.1016/j.joca.2015.04.005. ISSN 1522-9653. PMID 25914044.
- Haslerud, Sturla; Magnussen, Liv Heide; Joensen, Jon; Lopes-Martins, Rodrigo Alvaro Brandao; Bjordal, Jan Magnus (2015-06-01). "The efficacy of low-level laser therapy for shoulder tendinopathy: a systematic review and meta-analysis of randomized controlled trials". Physiotherapy Research International: The Journal for Researchers and Clinicians in Physical Therapy. 20 (2): 108–125. doi:10.1002/pri.1606. ISSN 1471-2865. PMID 25450903.
- Page, MJ; Green, S; Kramer, S; Johnston, RV; McBain, B; Buchbinder, R (Oct 1, 2014). "Electrotherapy modalities for adhesive capsulitis (frozen shoulder).". The Cochrane database of systematic reviews. 10: CD011324. doi:10.1002/14651858.CD011324. PMID 25271097.
- Nampo, Fernando Kenji; Cavalheri, Vinícius; Ramos, Solange de Paula; Camargo, Enilton Aparecido (2016-01-01). "Effect of low-level phototherapy on delayed onset muscle soreness: a systematic review and meta-analysis". Lasers in Medical Science. 31 (1): 165–177. doi:10.1007/s10103-015-1832-4. ISSN 1435-604X. PMID 26563953.
- Ferraresi, C; Hamblin, MR; Parizotto, NA (1 November 2012). "Low-level laser (light) therapy (LLLT) on muscle tissue: performance, fatigue and repair benefited by the power of light.". Photonics & lasers in medicine. 1 (4): 267–286. doi:10.1515/plm-2012-0032. PMC . PMID 23626925.
- Karlsson, M. R.; Diogo Löfgren, C. I.; Jansson, H. M. (2008). "The Effect of Laser Therapy as an Adjunct to Non-Surgical Periodontal Treatment in Subjects with Chronic Periodontitis: A Systematic Review". Journal of Periodontology. 79 (11): 2021–2028. doi:10.1902/jop.2008.080197. PMID 18980508.
- Sgolastra, F.; Petrucci, A.; Severino, M.; Gatto, R.; Monaco, A. (2013-06-01). "Lasers for the treatment of dentin hypersensitivity: a meta-analysis". Journal of Dental Research. 92 (6): 492–499. doi:10.1177/0022034513487212. ISSN 1544-0591. PMID 23609160.
- Eslamian, L.; Borzabadi-Farahani, A.; Hassanzadeh-Azhiri, A.; Badiee, M.R.; Fekrazad, R. (2013-01-20). "The effect of 810-nm low-level laser therapy on pain caused by orthodontic elastomeric separators". Lasers in Medical Science. 29 (2): 559–564. doi:10.1007/s10103-012-1258-1. PMID 23334785.
- Ren, Chong; McGrath, Colman; Yang, Yanqi (2015-09-01). "The effectiveness of low-level diode laser therapy on orthodontic pain management: a systematic review and meta-analysis". Lasers in Medical Science. 30 (7): 1881–1893. doi:10.1007/s10103-015-1743-4. ISSN 1435-604X. PMC . PMID 25800534.
- He, W. L.; Yu, F. Y.; Li, C. J.; Pan, J.; Zhuang, R.; Duan, P. J. (2015-08-01). "A systematic review and meta-analysis on the efficacy of low-level laser therapy in the management of complication after mandibular third molar surgery". Lasers in Medical Science. 30 (6): 1779–1788. doi:10.1007/s10103-014-1634-0. ISSN 1435-604X. PMID 25098769.
- Oberoi, Sapna; Zamperlini-Netto, Gabriele; Beyene, Joseph; Treister, Nathaniel S.; Sung, Lillian (2014-01-01). "Effect of prophylactic low level laser therapy on oral mucositis: a systematic review and meta-analysis". PLOS ONE. 9 (9): e107418. doi:10.1371/journal.pone.0107418. ISSN 1932-6203. PMC . PMID 25198431.
- Rogers, NE; Avram, MR (October 2008). "Medical treatments for male and female pattern hair loss.". Journal of the American Academy of Dermatology. 59 (4): 547–66; quiz 567–8. doi:10.1016/j.jaad.2008.07.001. PMID 18793935.
- Rangwala, Sophia; Rashid, Rashid M. (Feb 2012). "Alopecia: a review of laser and light therapies". Dermatology Online Journal. 18 (2): 3. ISSN 1087-2108. PMID 22398224.
Since then, a number of studies have suggested the use of lasers as an effective way to treat alopecia, particularly androgenetic alopecia and alopecia areata, but there is still a paucity of independent, peer-reviewed blinded clinical trials.
- Avci, Pinar; Gupta, Gaurav K.; Clark, Jason; Wikonkal, Norbert; Hamblin, Michael R. (2014-2). "Low-Level Laser (Light) Therapy (LLLT) for Treatment of Hair Loss". Lasers in surgery and medicine. 46 (2): 144–151. doi:10.1002/lsm.22170. ISSN 0196-8092. PMC . PMID 23970445. Check date values in:
- Gupta, AK; Daigle, D (April 2014). "The use of low-level light therapy in the treatment of androgenetic alopecia and female pattern hair loss.". The Journal of dermatological treatment. 25 (2): 162–3. doi:10.3109/09546634.2013.832134. PMID 23924031.
- Zarei, Mina; Wikramanayake, Tongyu C.; Falto-Aizpurua, Leyre; Schachner, Lawrence A.; Jimenez, Joaquin J. (2015-12-21). "Low level laser therapy and hair regrowth: an evidence-based review". Lasers in Medical Science. 31: 363–71. doi:10.1007/s10103-015-1818-2. ISSN 1435-604X. PMID 26690359.
- Smoot, Betty; Chiavola-Larson, Laura; Lee, Jeannette; Manibusan, Hidelisa; Allen, Diane D. (2015-06-01). "Effect of low-level laser therapy on pain and swelling in women with breast cancer-related lymphedema: a systematic review and meta-analysis". Journal of Cancer Survivorship: Research and Practice. 9 (2): 287–304. doi:10.1007/s11764-014-0411-1. ISSN 1932-2267. PMID 25432632.
- Barrett, S (June 17, 2009). "A Skeptical Look at Low Level Laser Therapy". Quackwatch.
- Chung, Hoon; Dai, Tianhong; Sharma, Sulbha K.; Huang, Ying-Ying; Carroll, James D.; Hamblin, Michael R. (2012-02-01). "The nuts and bolts of low-level laser (light) therapy". Annals of Biomedical Engineering. 40 (2): 516–533. doi:10.1007/s10439-011-0454-7. ISSN 1573-9686. PMC . PMID 22045511.
- Prindeze, Nicholas J.; Moffatt, Lauren T.; Shupp, Jeffrey W. (2012-11-01). "Mechanisms of action for light therapy: a review of molecular interactions". Experimental Biology and Medicine (Maywood, N.J.). 237 (11): 1241–1248. doi:10.1258/ebm.2012.012180. ISSN 1535-3699. PMID 23239434.
- Perera, Judith (19 March 1987). "The 'healing laser' comes into the limelight'". New Scientist.
- Chung, H; et al. (February 2012). "The nuts and bolts of low-level laser (light) therapy.". Annals of biomedical engineering. 40 (2): 516–33. doi:10.1007/s10439-011-0454-7. PMC . PMID 22045511.
- Hamblin, MR (1 October 2016). "Shining light on the head: Photobiomodulation for brain disorders.". BBA clinical. 6: 113–124. doi:10.1016/j.bbacli.2016.09.002. PMC . PMID 27752476.
- "Celebrating the 100th birthday of Professor Endre Mester". Laser World. Swedish Laser-Medical Society. April 18, 2004. Archived from the original on March 3, 2016.
- "Doggone Joints: Laser Therapy for Pet Arthritis". ABC News. 2011-02-23. Retrieved 2016-07-19.
- Robinson, Narda G. (2013), “Complementary and Alternative Veterinary Medicine: Laser Therapy”, The Merck Veterinary Manual, 11th edition.
- McKenzie, Brennen (2016), “The Laser Craze: What Is the Evidence for Low-level Laser Therapy?” [SA222]; Western Veterinary Conference, Proceedings of the WVC 88th Annual Conference, Mandalay Bay Convention Center, Resort and Casino, Las Vegas, NV, March 6-10, 2016.
- McKenzie, Brennen (2016), "WVC 2016: The Laser Craze", The SkeptVet.
- McKenzie, Brennen (2015), “Evidence Update: Cold Laser Therapy for Dogs & Cats”; The SkeptVet.
- Borzabadi-Farahani, A. (2016-07-22). "Effect of low-level laser irradiation on proliferation of human dental mesenchymal stem cells; a systemic review.". Journal of Photochemistry and Photobiology B: Biology. 162: 577–582. doi:10.1016/j.jphotobiol.2016.07.022. PMID 27475781.