Low-level laser therapy | |
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MeSH | D028022 |
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]
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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.
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.
Concerns have been raised in the literature about brain stimulation techniques that rely upon low-level (low-power) lasers and light-emitting diodes (LEDs). The transcranial photobiomodulation or transcranial low level light therapy is limited in neuromodulation due to several reasons:
Veterinary clinics use cold laser devices to treat a wide variety of ailments, from arthritis to wounds, on dogs and cats. [29] [30] 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". [31] [32] 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.
Faroese physician Niels Finsen is believed to be the father of modern light therapy. [33] He used red light to treat smallpox lesions. He received the Nobel Prize in Physiology or Medicine in 1903. [34] 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. [35]
Hungarian physician and surgeon Endre Mester (1903–1984) is credited with the discovery of the biological effects of low power lasers, [36] 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 was not 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. [37] His sons carried on his work and brought it to the United States. [36] 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. [36] 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]
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, [38] 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. [39] 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), [40] or transcranial low level light therapy.
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. [41]
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. [42] [43]
The examples and perspective in this section may not represent a worldwide view of the subject.(January 2024) |
Blue Cross Blue Shield Association and Aetna provide coverage for the prevention of oral mucositis, but not any other reason. [44] [45] The Centers for Medicare and Medicaid Services does not provide coverage for LLLT. [46] Cigna lists LLLT as "experimental, investigational, or unproven for any indication" and provides literature review summaries for a number of conditions. [47]
Evidence does not support a benefit in delayed-onset muscle soreness. [48] It may be useful for muscle pain and injuries. [49] A 2008 Cochrane Library review concluded that LLLT has insufficient evidence for treatment of nonspecific low back pain, [50] a finding echoed in a 2010 review of chronic low back pain. [51] A 2015 review found benefit in nonspecific chronic low-back pain. [15] 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. [52] In a study testing the efficacy of low-level laser therapy treating plantar fasciitis found that LLLT significantly reduces pain in lower extremity tendinopathy and plantar fasciitis in the short and medium terms. [53] The same study also stated that while comparing the effect of LLLT to that of therapeutic ultrasound in persons with patellar tendinopathy, and they found a statistically significant effect in favour of LLLT, both on pain reduction and function. [54]
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] Research that compared the effects of LLLT against other treatments, sham treatments, or no treatment at all, and randomized adult patients with rheumatoid arthritis to receive it were considered. These outcomes included pain, functional capacity, adverse events, inflammation, disease activity, range of motion, stiffness in the morning, muscle strength, and quality of life. [55] The findings indicate that the differences between utilizing a sham and an infrared laser may be negligible or nonexistent in terms of pain, stiffness in the morning, grip strength, functional ability, inflammation, range of motion, disease activity, and side events. We also discovered that the data about the effects of laser acupuncture against reflexology in terms of functional ability, quality of life, and inflammation is quite hazy, and about the effects of red laser versus sham in terms of pain, morning stiffness, and side events. [56] The usefulness of red laser, laser acupuncture, and reflexology in the treatment of RA patients is not well enough demonstrated. [57] 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. [58]
There is tentative evidence of benefit in tendinopathy. [9] [17] A 2014 review found benefit in shoulder tendinopathy. [59] A 2014 Cochrane review found tentative evidence that it may help in frozen shoulders. [60]
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. [61] There is tentative evidence for dentin hypersensitivity. [62] It does not appear to be useful for orthodontic pain [63] [64] LLLT might be useful for wisdom tooth extraction (complications). [65]
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. [66] A 2014 review found tentative evidence for benefit for lasers, [67] while another 2014 review concluded that the results were mixed, had a high risk of bias, and that its effectiveness was unclear. [68] A 2015 review found tentative evidence of benefit. [69] 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." [70]
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, [71] with more emphasis to be placed on lasers compared to LEDs. [72] Ultraviolet and infrared light are more effective for alopecia areata, while red light and infrared light is more effective for androgenetic alopecia. [73]
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. [74] [75] [76]
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.
LLLT has been studied as a way to reduce pain and swelling in breast-cancer related lymphedema. [77] [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.” [78]
An ongoing area of research is the application of LLLT for increasing cell proliferation, including stem cells. [79]
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. [80] However, as of 2012 [update] and due to inconsistent results and the low quality of extant research, reviews in the scientific literature have not supported its widespread application. [80] [81]
Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involved, with the same joints typically involved on both sides of the body. The disease may also affect other parts of the body, including skin, eyes, lungs, heart, nerves, and blood. This may result in a low red blood cell count, inflammation around the lungs, and inflammation around the heart. Fever and low energy may also be present. Often, symptoms come on gradually over weeks to months.
Chronic pain or chronic pain syndrome is a type of pain that is also known by other titles such as gradual burning pain, electrical pain, throbbing pain, and nauseating pain. This type of pain is sometimes confused with acute pain and can last from three months to several years; various diagnostic manuals such as DSM-5 and ICD-11 have proposed several definitions of chronic pain, but the accepted definition is that it is "pain that lasts longer than the expected period of recovery."
Tendinopathy is a type of tendon disorder that results in pain, swelling, and impaired function. The pain is typically worse with movement. It most commonly occurs around the shoulder, elbow, wrist, hip, knee, or ankle.
Fibromyalgia is a medical syndrome that causes chronic widespread pain, accompanied by fatigue, awakening unrefreshed, and cognitive symptoms. Other symptoms can include headaches, lower abdominal pain or cramps, and depression. People with fibromyalgia can also experience insomnia and general hypersensitivity. The cause of fibromyalgia is unknown, but is believed to involve a combination of genetic and environmental factors. Environmental factors may include psychological stress, trauma, and some infections. Since the pain appears to result from processes in the central nervous system, the condition is referred to as a "central sensitization syndrome".
Pain management is an aspect of medicine and health care involving relief of pain in various dimensions, from acute and simple to chronic and challenging. Most physicians and other health professionals provide some pain control in the normal course of their practice, and for the more complex instances of pain, they also call on additional help from a specific medical specialty devoted to pain, which is called pain medicine.
Osteoarthritis (OA) is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone. It is believed to be the fourth leading cause of disability in the world, affecting 1 in 7 adults in the United States alone. The most common symptoms are joint pain and stiffness. Usually the symptoms progress slowly over years. Other symptoms may include joint swelling, decreased range of motion, and, when the back is affected, weakness or numbness of the arms and legs. The most commonly involved joints are the two near the ends of the fingers and the joint at the base of the thumbs, the knee and hip joints, and the joints of the neck and lower back. The symptoms can interfere with work and normal daily activities. Unlike some other types of arthritis, only the joints, not internal organs, are affected.
Low back pain or lumbago is a common disorder involving the muscles, nerves, and bones of the back, in between the lower edge of the ribs and the lower fold of the buttocks. Pain can vary from a dull constant ache to a sudden sharp feeling. Low back pain may be classified by duration as acute, sub-chronic, or chronic. The condition may be further classified by the underlying cause as either mechanical, non-mechanical, or referred pain. The symptoms of low back pain usually improve within a few weeks from the time they start, with 40–90% of people recovered by six weeks.
Tennis elbow, also known as lateral epicondylitis or enthesopathy of the extensor carpi radialis origin, is an enthesopathy of the origin of the extensor carpi radialis brevis on the lateral epicondyle. Those with tennis elbow often report pain and tenderness over the bony prominence of the lateral epicondyle, which serves as the common origin of the forearm and hand’s long extensor tendons. Symptoms range from mild tenderness to severe, persistent pain. The pain may also extend into the back of the forearm. Onset of symptoms is generally gradual, although they can seem sudden and be misinterpreted as an injury.
Electrotherapy is the use of electrical energy as a medical treatment. In medicine, the term electrotherapy can apply to a variety of treatments, including the use of electrical devices such as deep brain stimulators for neurological disease. The term has also been applied specifically to the use of electric current to speed wound healing. The use of EMS is also very wide for managing muscular pain. Additionally, the term "electrotherapy" or "electromagnetic therapy" has also been applied to a range of alternative medical devices and treatments. Evidence supporting the effectiveness of electrotherapy is limited.
Prolotherapy, also called proliferation therapy, is an injection-based treatment used in chronic musculoskeletal conditions. It has been characterised as an alternative medicine practice.
The management of hair loss, includes prevention and treatment of alopecia, baldness, and hair thinning, and regrowth of hair.
Patellar tendinitis, also known as jumper's knee, is an overuse injury of the tendon that straightens the knee. Symptoms include pain in the front of the knee. Typically the pain and tenderness is at the lower part of the kneecap, though the upper part may also be affected. Generally there is no pain when the person is at rest. Complications may include patellar tendon rupture.
Therapeutic effect refers to the response(s) after a treatment of any kind, the results of which are judged to be useful or favorable. This is true whether the result was expected, unexpected, or even an unintended consequence. An adverse effect is the converse and refers to harmful or undesired response(s). What constitutes a therapeutic effect versus a side effect is a matter of both the nature of the situation and the goals of treatment. No inherent difference separates therapeutic and undesired side effects; both responses are behavioral/physiologic changes that occur as a response to the treatment strategy or agent.
Pattern hair loss is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front hairline, loss of hair on the crown and vertex of the scalp, or a combination of both. Female-pattern hair loss (FPHL) typically presents as a diffuse thinning of the hair across the entire scalp.
Extracorporeal shockwave therapy (ESWT) is a treatment using powerful acoustic pulses which is mostly used to treat kidney stones and in physical therapy and orthopedics.
Neck pain, also known as cervicalgia, is a common problem, with two-thirds of the population having neck pain at some point in their lives.
Hungarian physician Endre Mester (1903–1984) was a pioneer of laser medicine, especially the use of low level laser therapy (LLLT). In 1967, only a few years after the first working laser was invented, he started his experiments with the effects of lasers on skin cancer. He is credited as the discoverer of positive biological effects of low power lasers, which have been advocated as alternative medicine for use in wound healing, smoking cessation, tuberculosis, temporomandibular joint disorders, and musculoskeletal conditions such as carpal tunnel syndrome, fibromyalgia, osteoarthritis, and rheumatoid arthritis. LLLT devices are popular and may bring about temporary relief of some types of pain. As of 2009, a summary from Quackwatch reported medical authorities found no reason to believe LLLT influence the course of any ailment or are more effective for pain control than other forms of heat delivery. Subsequent research has found LLLT may offer benefit in treating several health ailments, including rheumatoid arthritis, osteoarthritis, tendinopathy, and frozen shoulders.
Platelet-rich plasma (PRP), also known as autologous conditioned plasma, is a concentrate of plasma protein derived from whole blood, centrifuged to remove red blood cells but retaining platelets. Though promoted for treating various medical conditions, evidence of its benefits was mixed as of 2020, showing effectiveness in certain conditions and ineffectiveness in others.
Fred Kahn was an American vascular surgeon who was the president and chief executive officer of Meditech International Inc., which he founded in 1989. The focus of the company has been to design and manufacture advanced Laser Therapy Systems under the brand name of BioFlex. BioFlex devices are widely utilized to treat both standard and complex medical conditions, many of which are resistant to conventional and traditional therapies.
Light-emitting diode therapy (LEDT) is a clinical approach that applies different wavelengths of light to cure diseases or conditions with skin-safe lights. Following NASA's innovation in the 1990s with Light Emitting Diodes (LEDs) that emit a specific narrow light spectrum, LED Therapy (LEDT) showed significant potential. The high precision of narrow-band LED therapy enabled its first use in clinical practices. The commonly used lights in LEDT are blue, red, green, yellow, and infrared (IR).
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: CS1 maint: DOI inactive as of November 2024 (link)his systematic review provides inconclusive evidence because of significant between-study heterogeneity and potential risk of bias.
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.