Physics:Low-level laser therapy

From HandWiki
Short description: Treatment using irradiation with light of low power intensity
Low-level laser therapy
Laserbehandling.jpg
LLLT being applied for rheumatism in Sweden
MeSHD028022

Low-level laser therapy (LLLT), cold laser therapy, photobiomodulation (PBM)[1][2][3][4] or red light therapy[5] is a form of medicine that applies low-level (low-power) lasers or light-emitting diodes (LEDs) to the surface of the body. Whereas high-power lasers are used in laser medicine to cut or destroy tissue, it is claimed that application of low-power lasers relieves pain or stimulates and enhances cell function. The effects appear to be limited to a specified set of wavelengths and new research has demonstrated effectiveness at myopia control.[6] Several such devices are cleared by the United States Food and Drug Administration (FDA), and research shows potential for treating a range of medical problems including rheumatoid arthritis[7] and oral mucositis.[8]

Mechanism

Research is ongoing about the mechanism of LLLT. The effects of LLLT appear to be limited to a specified set of wavelengths of laser,[9] and administering LLLT below the dose range does not appear to be effective.[10] Photochemical reactions are well known in biological research, and LLLT make use of the first law in photochemistry (Grotthuss-Draper law): light must be absorbed by a chemical substance in order for a photochemical reaction to take place. In LLLT that chemical substance is represented by the respiratory enzyme cytochrome c oxidase which is involved in the electron transport chain in mitochondria,[11][12] which is the generally accepted theory.

Medical uses

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 disorders, wound healing, smoking cessation, and tuberculosis. LLLT appears to be effective for preventing oral mucositis in recipients of a stem cell transplant with chemotherapy.[8][13] In other areas, evidence for LLLT remains conflicted. Some studies suggest that LLLT may be modestly effective in relieving short-term pain for rheumatoid arthritis,[7] osteoarthritis,[14] chronic low back pain,[15] acute and chronic neck pain,[16] tendinopathy,[9][17] and chronic joint disorders.[10] The evidence for LLLT being useful in dentistry,[18][19] and in the treatment of wound healing[20] is unclear.

Veterinary use

Veterinary clinics use cold laser devices to treat a wide variety of ailments, from arthritis to wounds, on dogs and cats.[21][22] Very little research has been done on the effects of this treatment on animals. Brennen McKenzie, president of the Evidence-Based Veterinary Medicine 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".[23][24] 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.

Society and culture

History

Faroese physician Niels Finsen is believed to be the father of modern light therapy.[25] He used red light to treat smallpox lesions. He received the Nobel Prize in Physiology or Medicine in 1903.[26] Scientific evidence for some of his treatments is lacking, and later eradication of smallpox and development of antibiotics for tuberculosis rendered light therapy obsolete for these diseases.[27]

Hungarian physician and surgeon Endre Mester (1903–1984) is credited with the discovery of the biological effects of low power lasers,[28] which occurred a few years after the 1960 invention of the ruby laser and the 1961 invention of the helium–neon (HeNe) laser.[11] 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 more quickly on the treated mice than on those among the control group.[2] He published those results in 1967.[11] He went on to show that low level HeNe light could accelerate wound healing in mice.[11]

By the 1970s, he was applying low level laser light to treat people with skin ulcers.[11] 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.[29] His sons carried on his work and brought it to the United States.[28] 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.[28] 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.[2]

Names

The following terms are accepted as alternatives of low level light therapy term: LLLT, laser biostimulation, laser phototherapy, low-level laser therapy, low-power laser irradiation, low-power laser therapy, and photobiomodulation therapy. The term photobiomodulation therapy is considered the preferred term by industry professionals.[3][4] However LLLT has been marketed and researched under a number of other terms, including red light therapy,[30] 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.[31] More specific applications sometimes have their own terms, for example when administered to acupuncture points, the procedure is called laser acupuncture. When applied to the head, LLLT may be known as transcranial photobiomodulation, transcranial near-infrared laser therapy (NILT),[32] or transcranial low level light therapy.

Government action

The FDA filed a complaint for injunction in 2014, alleging that company QLaser PMA were marketing their devices as being able to treat “over 200 different diseases and disorders,” including cancer, cardiac arrest, deafness, diabetes, HIV/AIDS, macular degeneration, and venereal disease. This case resulted in a permanent injunction against the manufacture, marketing, sale, and distribution of those devices in 2015.[33]

In 2017, the owner of QLaser, Robert Lytle, and two of QLaser's distributors were charged with a criminal conspiracy to commit fraud. Lytle pleaded guilty to one count of conspiracy to introduce misbranded medical devices into interstate commerce with the intent to defraud and mislead, and one count of criminal contempt in January 2018. Lytle was sentenced to serve 12 years in prison and made an initial restitution payment of $637,000. Lytle's conspirators were sentenced to 24 months and 15 months, respectively.[34][35]

Reimbursement

Blue Cross Blue Shield Association and Aetna provide coverage for the prevention of oral mucositis, but not any other reason.[36][37] The Centers for Medicare and Medicaid Services does not provide coverage for LLLT.[38] Cigna lists LLLT as "experimental, investigational, or unproven for any indication" and provides literature review summaries for a number of conditions.[39]

Research

Demonstration of LLLT with intranasal irradiation

Musculoskeletal

Evidence does not support a benefit in delayed-onset muscle soreness.[40] It may be useful for muscle pain and injuries.[41] A 2008 Cochrane Library review concluded that LLLT has insufficient evidence for treatment of nonspecific low back pain,[42] a finding echoed in a 2010 review of chronic low back pain.[43] A 2015 review found benefit in nonspecific chronic low-back pain.[44] LLLT may be useful in the treatment of both acute and chronic neck pain.[16] In 2013, however, a systematic review and meta-analysis of LLLT for neck pain indicated that the benefit was not of significant importance and that the evidence had a high risk of bias.[45]

There are tentative data that LLLT is useful in the short-term treatment of pain caused by rheumatoid arthritis,[7] and possibly chronic joint disorders.[10] A 2019 systematic review and meta-analysis found evidence for pain reduction in osteoarthritis.[14] While it does not appear to improve pain in temporomandibular disorders, it may improve function.[46]

There is tentative evidence of benefit in tendinopathy.[9][17] A 2014 review found benefit in shoulder tendinopathy.[47] A 2014 Cochrane review found tentative evidence that it may help in frozen shoulders.[48]

Mouth

Similarly, the use of lasers to treat chronic periodontitis[18] and to speed healing of infections around dental implants[19] is suggested, but there is insufficient evidence to indicate a use superior to traditional practices.[49] There is tentative evidence for dentin hypersensitivity.[50] It does not appear to be useful for orthodontic pain[51][52] LLLT might be useful for wisdom tooth extraction (complications).[53]

Hair loss

LLLT has been studied as a treatment for hair loss; a review in 2012 found little evidence to support the use of lasers to treat hair loss.[54] A 2014 review found tentative evidence for benefit for lasers,[55] while another 2014 review concluded that the results were mixed, had a high risk of bias, and that its effectiveness was unclear.[56] A 2015 review found tentative evidence of benefit.[57] Additionally, a 2017 review of clinical trials found 10 of 11 trials reviewed "demonstrated significant improvement of androgenic alopecia in comparison to baseline or controls when treated with LLLT."[58]

LLLT is shown to increase hair density and growth in both genders. The types of devices (hat, comb, helmet) and duration did not alter the effectiveness,[59] with more emphasis to be placed on lasers compared to LEDs.[60] Ultraviolet and infrared light are more effective for alopecia areata, while red light and infrared light is more effective for androgenetic alopecia.[61]

Medical reviews suggest that LLLT is as effective or potentially more than other non invasive and traditional therapies like minoxidil and finasteride but further studies such as RCTs, long term follow up studies, and larger double blinded trials need to be conducted to confirm the initial findings.[62][63][64]

Brain injuries

LLLT has been studied for traumatic brain injury (TBI) and stroke among other conditions.[11] When applied to the head it is known as transcranial photobiomodulation or transcranial low level light therapy.

Cancer treatment side effects

LLLT has been studied as a way to reduce pain and swelling in breast-cancer related lymphedema.[65][20] The 2015 systematic review & meta-analysis by Smoot, Chiavola-Larson, et al found: “Moderate-strength evidence supports LLLT in the management of [breast cancer related lymphoedema], with […] reductions in volume and pain immediately after conclusion of LLLT treatments. Greater reductions in volume [of lymph nodes or surrounding tissues] were found with the use of LLLT than in treatments without it.”[66]

Stem cells

An ongoing area of research is the application of LLLT for increasing cell proliferation, including stem cells.[67]

Wound healing

Low level laser therapy has been studied as a potential treatment for chronic wounds, and higher-power lasers have sometimes been successfully used to close acute wounds as an alternative to stitching.[68] However, (As of 2012) and due to inconsistent results and the low quality of extant research, reviews in the scientific literature have not supported its widespread application.[68][69]

See also

References

  1. Hamblin, Michael R. (2016). "Photobiomodulation or low-level laser therapy". Journal of Biophotonics 9 (11–12): 1122–1124. doi:10.1002/jbio.201670113. PMID 27973730. 
  2. 2.0 2.1 2.2 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. PMID 27752476. 
  3. 3.0 3.1 Hamblin, Michael R.; Carroll, James D.; de Freitas, Lucas Freitas; Huang, Ying-Ying; Ferraresi, Cleber (2018-01-12), "Introduction", Low-Level Light Therapy: Photobiomodulation (SPIE), doi:10.1117/3.2295638.ch1, ISBN 978-1-5106-1416-1, https://www.spiedigitallibrary.org/ebooks/TT/Low-Level-Light-Therapy-Photobiomodulation/1/Introduction/10.1117/3.2295638.ch1?SSO=1, retrieved 2021-02-11 
  4. 4.0 4.1 "Photobiomodulation". https://www.aslms.org/for-the-public/treatments-using-lasers-and-energy-based-devices/photobiomodulation. 
  5. Hamblin, Michael R.; Gupta, Asheesh (2013). "History and Fundamentals of Low-Level Laser (Light) Therapy". Handbook of Photomedicine. CRC Press. doi:10.1201/b15582-10. ISBN 978-0-429-19384-2. https://www.taylorfrancis.com/chapters/edit/10.1201/b15582-10/history-fundamentals-low-level-laser-light-therapy-asheesh-gupta-michael-hamblin. Retrieved 2023-09-04. 
  6. Jiang, Yu; Zhuoting, Zhu; Xingping, Tan; Xiangbin, Kong; Zhong, Hui; Zhang, Jian; Xiong, Ruilin; Yuan, Yixiong et al. (2021-12-01). "Effect of Repeated Low-Level Red-Light Therapy for Myopia Control in Children". https://www.aaojournal.org/article/S0161-6420(21)00916-7/fulltext. 
  7. 7.0 7.1 7.2 Brosseau, L.; Welch, V.; Wells, G. A.; de Bie, R.; Gam, A.; Harman, K.; Morin, M.; Shea, B. et al. (2005). "Low level laser therapy (Classes I, II and III) for treating rheumatoid arthritis". Cochrane Database of Systematic Reviews 2010 (4): CD002049. doi:10.1002/14651858.CD002049.pub2. PMID 16235295. 
  8. 8.0 8.1 Oberoi, S; Zamperlini-Netto, G; Beyene, J; Treister, NS; Sung, L (2014). "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. PMID 25198431. Bibcode2014PLoSO...9j7418O. 
  9. 9.0 9.1 9.2 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. PMID 18510742. 
  10. 10.0 10.1 10.2 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. 
  11. 11.0 11.1 11.2 11.3 11.4 11.5 Chung, Hoon; Dai, Tianhong; Sharma, Sulbha K.; Huang, Ying-Ying; Carroll, James D.; Hamblin, Michael R. (2011). "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 0090-6964. PMID 22045511. 
  12. 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 237 (11): 1241–1248. doi:10.1258/ebm.2012.012180. ISSN 1535-3699. PMID 23239434. 
  13. On behalf of The Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO); Zadik, Yehuda; Arany, Praveen R.; Fregnani, Eduardo Rodrigues; Bossi, Paolo; Antunes, Héliton Spindola; Bensadoun, René-Jean; Gueiros, Luiz Alcino et al. (October 2019). "Systematic review of photobiomodulation for the management of oral mucositis in cancer patients and clinical practice guidelines". Supportive Care in Cancer 27 (10): 3969–3983. doi:10.1007/s00520-019-04890-2. ISSN 0941-4355. PMID 31286228. 
  14. 14.0 14.1 Stausholm, Martin Bjørn; Naterstad, Ingvill Fjell; Joensen, Jon; Lopes-Martins, Rodrigo Álvaro Brandão; Sæbø, Humaira; Lund, Hans; Fersum, Kjartan Vibe; Bjordal, Jan Magnus (2019-10-28). "Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials". BMJ Open 9 (10): e031142. doi:10.1136/bmjopen-2019-031142. ISSN 2044-6055. PMID 31662383. 
  15. Huang, ZeYu; Ma, Jun; Chen, Jing; Shen, Bin; Pei, FuXing; Kraus, Virginia Byers (2015-12-15). "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. PMID 26667480. 
  16. 16.0 16.1 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. 
  17. 17.0 17.1 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. 
  18. 18.0 18.1 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. 
  19. 19.0 19.1 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:10.1586/17434440.2.3.267. PMID 16288590. 
  20. 20.0 20.1 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. 
  21. "Doggone Joints: Laser Therapy for Pet Arthritis". ABC News. 2011-02-23. https://abcnews.go.com/Health/laser-therapy-staves-off-pets-arthritis/story?id=12974694. 
  22. Robinson, Narda G. (2013), "Complementary and Alternative Veterinary Medicine: Laser Therapy", The Merck Veterinary Manual, 11th edition.
  23. 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.
  24. McKenzie, Brennen (2016), "WVC 2016: The Laser Craze", The SkeptVet.
  25. Ingold, Niklaus (2015) (in German). Lichtduschen Geschichte einer Gesundheitstechnik, 1890–1975. Chronos Verlag. pp. 40–49. ISBN 978-3-0340-1276-8. https://library.oapen.org/handle/20.500.12657/31817. 
  26. "The Nobel Prize in Physiology or Medicine 1903". Nobel Media AB. 2016-11-01. https://www.nobelprize.org/nobel_prizes/medicine/laureates/1903/. 
  27. "Engines of our Ingenuity No. 1769: NIELS FINSEN". http://www.uh.edu/engines/epi1769.htm. 
  28. 28.0 28.1 28.2 Perera, Judith (19 March 1987). "The 'healing laser' comes into the limelight'". New Scientist. https://books.google.com/books?id=qxwPsfm2RS8C&pg=PA32. 
  29. "Celebrating the 100th birthday of Professor Endre Mester". Swedish Laser-Medical Society. April 18, 2004. http://www.laser.nu/lllt/endre_mester_100_year.htm. 
  30. "What Is Red Light Therapy?" (in en). https://www.webmd.com/skin-problems-and-treatments/red-light-therapy. 
  31. American Cancer Society. Cold Laser Therapy Page archived April 24, 2015
  32. Lapchak, PA (December 2010). "Taking a light approach to treating acute ischemic stroke patients: transcranial near-infrared laser therapy translational science". Annals of Medicine 42 (8): 576–86. doi:10.3109/07853890.2010.532811. PMID 21039081. 
  33. "District Court Grants Permanent Injunction Against Device Maker" (in en-US). 5 May 2018. https://www.policymed.com/2015/10/district-court-grants-permanent-injunction-against-device-maker.html. 
  34. Hein, Alexandria (2018-04-24). "'QLaser' TV infomercial doc gets 12 years in prison for selling scam device" (in en-US). https://www.foxnews.com/health/qlaser-tv-infomercial-doc-gets-12-years-in-prison-for-selling-scam-device. 
  35. "A Skeptical Look at Low Level Laser Therapy | Quackwatch" (in en-US). 26 April 2018. https://quackwatch.org/device/reports/lllt/. 
  36. Blue Cross and Blue Shield of Kansas City (Blue KC). "Low-Level Laser Therapy". http://medicalpolicy.bluekc.com/MedPolicyLibrary/Medicine/Standard%20Medicine/06-18_2_Low_Level_Laser_Therapy.pdf.  (Policy reviewed each June; if link is dead try replacing "06-18" with a more recent year.)
  37. "Infrared therapy". Aetna clinical policy bulletin 0363, reviewed June 17, 2020. Aetna has additional information in its "Clinical Policy Bulletin on Cold Laser and High-Power Laser Therapies".
  38. "Decision memo for infrared therapy devices" (CAG00291N). Center for Medicare & Medicaid Services, Oct 24, 2006.
  39. "Cigna Medical Coverage Policy- Therapy Services Low-Level Laser and High-Power Laser Therapy". https://static.cigna.com/assets/chcp/pdf/coveragePolicies/medical/CPG030_laser_therapy.pdf. 
  40. 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. 
  41. 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. PMID 23626925. 
  42. Yousefi-Nooraie, R.; Schonstein, E.; Heidari, K.; Rashidian, A.; Pennick, V.; Akbari-Kamrani, M.; Irani, S.; Shakiba, B. et al. (2008). Yousefi-Nooraie, Reza. ed. "Low level laser therapy for nonspecific low-back pain". Cochrane Database of Systematic Reviews 2011 (2): CD005107. doi:10.1002/14651858.CD005107.pub4. PMID 18425909. PMC 9044120. http://researchonline.lshtm.ac.uk/8828/1/Yousefi-Nooraie_et_al-2007-The_Cochrane_library.pdf. 
  43. 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. PMID 20640863. 
  44. 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. PMID 26667480. 
  45. 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.". 
  46. 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. 
  47. 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 20 (2): 108–125. doi:10.1002/pri.1606. ISSN 1471-2865. PMID 25450903. 
  48. 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 (10): CD011324. doi:10.1002/14651858.CD011324. PMID 25271097. 
  49. 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. 
  50. 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. 
  51. 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. 
  52. 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. PMID 25800534. 
  53. 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. 
  54. Rangwala, Sophia; Rashid, Rashid M. (Feb 2012). "Alopecia: a review of laser and light therapies". Dermatology Online Journal 18 (2): 3. doi:10.5070/D31JT041T2. 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.". 
  55. Avci, Pinar; Gupta, Gaurav K.; Clark, Jason; Wikonkal, Norbert; Hamblin, Michael R. (February 2014). "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. PMID 23970445. 
  56. 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. 
  57. 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 (2): 363–71. doi:10.1007/s10103-015-1818-2. ISSN 1435-604X. PMID 26690359. 
  58. Darwin, Evan; Heyes, Alexandra; Hirt, Penelope A.; Wikramanayake, Tongyu; Jimenez, Joaquin J. (2018). "Low-level laser therapy for the treatment of androgenic alopecia: a review". Lasers in Medical Science 33 (2): 425–434. doi:10.1007/s10103-017-2385-5. PMID 29270707. 
  59. Liu, Kao-Hui; Liu, Donald; Chen, Yu-Tsung; Chin, Szu-Ying (2019-01-31). "Comparative effectiveness of low-level laser therapy for adult androgenic alopecia: a system review and meta-analysis of randomized controlled trials". Lasers in Medical Science (Springer Science and Business Media LLC) 34 (6): 1063–1069. doi:10.1007/s10103-019-02723-6. ISSN 0268-8921. PMID 30706177. 
  60. Gupta, A. K.; Carviel, J. L. (2019-11-20). "Meta-analysis of photobiomodulation for the treatment of androgenetic alopecia". Journal of Dermatological Treatment (Informa UK Limited) 32 (6): 643–647. doi:10.1080/09546634.2019.1688755. ISSN 0954-6634. PMID 31746251. 
  61. Zhang, Yuehou; Su, Jianlong; Ma, Kui; Fu, Xiaobing; Zhang, Cuiping (2022-04-25). "Photobiomodulation Therapy With Different Wavebands for Hair Loss: A Systematic Review and Meta-Analysis". Dermatologic Surgery (Ovid Technologies (Wolters Kluwer Health)) 48 (7): 737–740. doi:10.1097/dss.0000000000003472. ISSN 1076-0512. PMID 35510860. 
  62. Gupta, Aditya K.; Bamimore, Mary A.; Foley, Kelly A. (2020-04-13). "Efficacy of non-surgical treatments for androgenetic alopecia in men and women: a systematic review with network meta-analyses, and an assessment of evidence quality". Journal of Dermatological Treatment (Informa UK Limited) 33 (1): 62–72. doi:10.1080/09546634.2020.1749547. ISSN 0954-6634. PMID 32250713. https://figshare.com/articles/journal_contribution/12087042. 
  63. Darwin, Evan; Heyes, Alexandra; Hirt, Penelope A.; Wikramanayake, Tongyu Cao; Jimenez, Joaquin J. (2017-12-21). "Low-level laser therapy for the treatment of androgenic alopecia: a review". Lasers in Medical Science (Springer Science and Business Media LLC) 33 (2): 425–434. doi:10.1007/s10103-017-2385-5. ISSN 0268-8921. PMID 29270707. 
  64. S, Lueangarun; P, Visutjindaporn; Y, Parcharoen; P, Jamparuang; T, Tempark (2021). "A Systematic Review and Meta-analysis of Randomized Controlled Trials of United States Food and Drug Administration-Approved, Home-use, Low-Level Light/Laser Therapy Devices for Pattern Hair Loss: Device Design and Technology". The Journal of Clinical and Aesthetic Dermatology 14 (11): E64–E75. ISSN 1941-2789. PMID 34980962. 
  65. 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. 
  66. Smoot, Betty; Chiavola-Larson, Laura; Lee, Jeannette; Manibusan, Hidelisa; Allen, Diane D. (2015). "Effect of low-level laser therapy on pain and swelling in women with breast cancer-related lymphedema: a systematic review and meta-analysis" (in en). Journal of Cancer Survivorship 9 (2): 287–304. doi:10.1007/s11764-014-0411-1. ISSN 1932-2259. http://link.springer.com/10.1007/s11764-014-0411-1. 
  67. 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. 
  68. 68.0 68.1 Nouri K, ed (2012). "Laser and Light for Wound Healing Stimulation". Lasers in Dermatology and Medicine. Springer London.. pp. 267–275. doi:10.1007/978-0-85729-281-0_20. ISBN 978-0857292810. 
  69. "Low-level laser therapy for wound healing: mechanism and efficacy". Dermatol Surg 31 (3): 334–340. 2005. doi:10.1111/j.1524-4725.2005.31086. PMID 15841638.