Scientific evidence has been accumulating over the last 10 years regarding the usefulness of high-intensity laser therapy (HILT) for the treatment of a variety of acute and chronic pain syndromes. This nonpharmacologic therapy may also prove to be an effective approach for reducing dependence on prescription opioid medication, thereby helping to resolve the current opioid crisis in this country.
Devices used for HILT operate at wavelengths between 660 and 1,275 nm and at power levels from 1 to 75 watts (Table). Compared with low-level laser devices (<1 watt), these HILT devices can penetrate tissue to depths ranging from 5 to 15 cm while producing only low levels of thermal accumulation in the tissue.
As a result of the opioid epidemic, physicians are increasingly searching for non-opioid alternatives to manage their patients’ pain needs. Nonopioid analgesic therapies have proven to be highly effective as part of a multimodal (“balanced”) analgesic treatment regimen (White PF. Expert Opin Pharmacother 2017;18:329-333). These techniques include infiltration of the surgical incision site with local anesthetics, and single-shot and continuous peripheral nerve block techniques. Parenteral ketorolac and other injectable nonsteroidal anti-inflammatory drugs (NSAIDs), as well as acetaminophen, are valuable adjuncts to local anesthetics during the perioperative period.
|Table. Comparison of Low-Level Laser Therapy (LLLT) and High-Intensity Laser Therapy (HILT) Devices Used to Treat Acute and Chronic Pain Syndromes.a|
|Class||I, Im, II, III||IV|
|Wavelength||600-980 nm||660-1,275 nm|
|Power||5-500 mW||1-75 W|
|Tissue penetration||Low (<2 cm)||Deep (5-15 cm)|
|Temperature change||<1.0° C||Low thermal accumulation|
|Applications for acute and chronic pain conditions||Carpal tunnel syndrome
Low back pain
Medial and lateral epicondylitis
Nipple lesion–induced pain
Superficial postoperative pain
Temporomandibular joint pain
The pain of muscle injury
Low back pain
Medial and lateral epicondylitis
Recovery of nerve paralysis
The pain of muscle injury
|Examples of laser systems||Helium-neon (HeNe) Gallium arsenide (GaAs) Aluminium gallium indium phosphide (InGaAlP) As-Ga-Al Erchonia||Nd:YAG laser Phoenix Thera-Lase LightForce/LiteCure K Laser|
a Courtesy of Paul F. White, PhD, MD (from White et al. Rheumatol Int. 2017 [in press]).
HILT, high-intensity laser therapy; LLLT, low-level laser therapy; mW, milliwatts; nm, nanometers
“By using a combination of nonopioid analgesics, such as local anesthetics and NSAIDs (e.g., ketorolac, ibuprofen, naproxen, diclofenac, COX-2 inhibitors like celecoxib and meloxicam), as well as a variety of other nonopioid analgesics—e.g., acetaminophen, ketamine, clonidine, gabapentin—it is possible to minimize the need for opioid medication,” said Paul F. White, PhD, MD, a consultant in the Department of Anesthesiology at Cedars-Sinai Medical Center, in Los Angeles. Dr. White is also president of The White Mountain Institute at The Sea Ranch, Calif., and a member of the advisory board of Anesthesiology News.
The Advent of HILT
“In my opinion, opioids should be used primarily as ‘rescue’ analgesics when pain cannot be adequately controlled by preventative use of nonopioid analgesic drugs, as well as nonpharmacologic techniques, like electroanalgesia and laser therapy. The clinical benefits of these nonpharmacologic techniques have been underutilized in clinical practice because they are not being promoted to the medical community by industry, and reimbursement by third-party payors further discourages their use in mainstream medicine. A surprisingly large number of sham-controlled studies have demonstrated the clinical benefits of these noninvasive therapies in improving pain control and functional recovery when administered as adjuvants to commonly used pharmaceutical and physical therapy modalities.”
Compared with electroanalgesia and exercise therapies, use of laser therapy is a relatively recent development in pain management. The first cold laser was approved by the FDA for treating pain in 2001, and low-level laser therapy (LLLT) has only been used in the United States since 2002. HILT, known also as laser heat therapy, is an even more recent development, with the first peer-reviewed publications appearing in 2011. Laser therapy involves a simple, noninvasive, “point-and-shoot” technique that can be performed by trained laser technicians.
Cellular chromophores are presumed to be the receptor sites responsible for the beneficial effects of the laser light beam, including both cytochrome c oxidase (with absorption peaks in the near-infrared range) and photoactive porphyrins. Mitochondria are also thought to be affected by infrared light, leading to increased ATP production, modulation of reactive oxygen species and induction of transcription factors. These effects lead to increased cell proliferation and migration, particularly by fibroblasts; reduction in the levels of cytokines, growth factors and inflammatory mediators; and increased tissue oxygenation, all enhancing control of the inflammatory process, reducing pain and improving wound healing.
“Based on my group’s recently published articles describing preliminary studies with a powerful HILT device, which can produce up to 75 watts of power [Phoenix Thera-Lase, manufactured by Phoenix Thera-Lase Systems LLC], and clinical trials by many other investigators around the world, using both LLLT and HILT, it has become increasingly evident that laser therapy has many potentially important medical applications,” said Dr. White, who is also a consultant to Phoenix Thera-Lase Systems LLC. “We are in the process of organizing clinical studies to improve our understanding of when and how to optimally utilize these more powerful laser devices that have recently been introduced into clinical practice.”
Postsurgical Opioid Dependence: 3 Cases
Medical treatment of postsurgical pain with opioid analgesics has become an increasingly common gateway to opioid addiction. Physicians who use multimodal analgesic techniques in the perioperative period are in the best position to reduce opioid addiction by relying less heavily on opioid analgesics for treating both acute and chronic postsurgical pain. HILT can be a useful appro
ach for treating long-term opioid use after surgery. Dr. White and his colleagues presented data on three patients at the 2017 annual meeting of the Society for Ambulatory Surgery, and the case series was subsequently published in the Journal of Clinical Anesthesia (2017;40:51-53). All three cases involved patients who had become dependent on opioid analgesics following surgical procedures. Each patient underwent a series of eight to 12 laser treatments in an effort to reduce their chronic pain and dependence on opioid-containing pain medications.
A 32-year-old woman was involved in a motor vehicle accident 16 months prior to laser treatment. She sustained serious orthopedic injuries requiring multiple surgical procedures, including placement of a titanium rod in her left femur.
She was discharged from the hospital after 10 days, with morphine and hydromorphone for pain. Her regimen was later changed to hydrocodone-acetaminophen tablets because of side effects. She had physical therapy, but continuing pain required opioids for effective analgesia.
The patient initially presented for laser treatments in early December 2016. At that time, she was taking one tablet of hydrocodone bitartrate and acetaminophen 10 mg/325 mg four times daily along with ibuprofen 600 mg three times daily. Her baseline pain score was 4 to 5 at rest and 7 to 8 with physical activity on the 11-point pain verbal rating scale (VRS).
The eight treatment sessions each lasted 20 to 30 minutes and were distributed over a four-week period. Her lower back, left hip and left knee, which were the areas where she felt considerable pain, were treated with a series of 60-second treatments located approximately 3 to 5 inches apart while holding the laser hand piece 12 to 16 inches from the skin surface to avoid overheating.
At the end of the four-week treatment period, the patient’s pain at rest was reduced to a VRS score of 2 and increased to 3 with physical activity. She was able to discontinue opioid-containing analgesic medications and resumed normal activities of daily living, including hiking and water aerobics. She took one opioid-containing tablet approximately a month after the last laser treatment in the series because of pain after a day of moving into a new apartment. She is currently taking oral ibuprofen 600 mg twice daily as needed for pain associated with physical activity. She has resumed her normal activities and no longer relies on opioid medication for pain control.
A 64-year-old man sustained injuries to his lower back in a work-related accident approximately 20 years before initiating treatment. He underwent spine surgery and was discharged from the hospital with a prescription for hydrocodone-acetaminophen tablets to treat postsurgical low back pain. Approximately one year ago, he switched to tramadol and was initially taking eight to 10 tablets per day. Because of persistent pain despite the use of tramadol, he inquired about laser therapy in September 2016.
At the start of the laser treatments, his baseline pain VRS scores were 5 at rest and 7 with physical activity, despite regular use of tramadol. The patient received a series of 12 HILT treatments lasting 30 to 40 minutes over a six-week period. The laser was directed to his mid- and low back region and left hip.
At the end of the six-week treatment period, pain at rest was reduced to VRS 1 and increased to 2 following vigorous activity. The patient was able to decrease his tramadol consumption to one tablet per day over the last two months while continuing to increase physical activity. After completing the series of 12 laser treatments, he was able to participate in daily physical activities with his grandchildren.
A 44-year-old woman had chronic pain of the lumbar spine and hips after undergoing back surgery about 10 years earlier. Because of persistent severe pain despite taking two to three tablets of oxycodone 5 mg/acetaminophen 325 mg per day, she received a series of HILT treatment sessions in November 2016.
At that time, her baseline pain VRS score was 7 at rest and 10 with physical activity. The patient received a series of nine laser treatment sessions. The laser energy was directed to her low back and hip region, with each treatment lasting 30 to 40 minutes over a three-week period. At the end of the treatment period, her pain was reduced to 0 at rest and 3 with normal activities of daily living (e.g., working in her garden) without any opioid-containing pain medications. She reported being “opioid-free” when contacted a month after her last laser treatment session.
“These cases suggest that HILT can help patients discontinue long-term dependence on opioid medication by reducing their pain to a level that no longer requires treatment with opioid analgesics,” Dr. White reported. “This powerful 42-watt laser was able to facilitate the process of weaning patients off chronic opioid use, and hopefully can be utilized more widely to prevent long-term abuse of these highly addictive compounds.”
Degenerative Joint Diseases in Former Professional Athletes
Physicians prescribe oral opioids for osteoarthritis (OA) patients with severe degenerative joint disease, many of whom will progress to arthroplasty. Goesling et al (Pain 2016;157:1259-1265) reported that many patients who were already taking opioid analgesics, as well as opioid-naive patients, continue using opioids after arthroplasty surgery despite the absence of joint pain. In a controlled study, Ip demonstrated that adjunctive use of laser therapy in elderly patients with OA of the knee significantly prolonged the time to requiring joint replacement surgery (Laser Med Sci2015;30:2335-2339).
One group of individuals in whom OA of the knee (as well as the shoulder, ankle and spine) is especially common is former athletes. Dr. White and his colleagues recently published results of a case series that examined the effects of HILT on OA-related pain in former National Football League (NFL) players (J Mol Biomark Diagn 2017;8:343). The study included 39 men with OA who underwent one to three treatment sessions lasting 15 to 20 minutes. Pain was recorded at rest and with movement of the painful extremity before and after each treatment session. These investigators also assessed the duration of analgesia associated with each laser treatment, as well as effects on other OA-related symptoms. In these cases, the HILT was administered using the Phoenix Thera-Lase at a power of 42 watts and a wavelength of 1,275 nm.
Changes in Pain Scores
The researchers observed that VRS pain scores were significantly reduced both at rest and with activity after each HILT session. For instance, baseline pain VRS scores were 3.5±2.9 at rest and 6.0±2.6 with activity. After the first treatment, the pain scores decreased to 1.2±1.8 (P<0.01) at rest and 2.0±2.0 (P<0.01) with activity. The overall beneficial effect was 7.2±1.8 on a scale from 0=no relief to 10=complete relief, and the duration of the beneficial effect was one to three weeks in 64% of the players treated. Based on a survey administered to the patients, 90% reported that they would recommend the treatment modality to their colleagues and would be willing to pay out-of-pocket to receive laser treatments in the future.
“High-intensity laser treatments reduced chronic OA-related pain in these former NFL football players by about 67% at rest and with activity, and the beneficial effect typically persisted for one week or longer after only one to three treatments in the majority of these patients with chronic pain,” the researchers concluded.
Dr. White and his colleagues treated a patient with chronic pain due to drug-resistant fibromyalgia syndrome for more than seven years. This 67-year-old female veterinarian presented to the Eugene McDermott Center for Pain Management, in Dallas, in October 2016. Her baseline pain score was 6 to 7 on the 11-point pain VRS. She completed standard questionnaires to assess her fibromyalgia-like symptoms. Her widespread pain index score was 10/18, and symptom severity scores were 6/9 (Part A) and 1/3 (Part B). Her symptom impact questionnaire score was 38.3/100, with difficulty primarily expressed for performing household chores, lifting and carrying groceries, climbing stairs and prolonged sitting (>45 minutes).
The patient’s symptoms often prevented her from accomplishing her daily goals. She reported symptoms of depression; difficulty sleeping; memory and balance problems; and sensitivity to touch, loud noises, bright lights, odors and cold exposure. She also completed a RAND 36-Item Short Form Survey Instrument, with scores of 45/100 on the physical functioning subscale, 0/100 on the role limitations due to physical health and emotional problems subscales, 30/100 on the energy/fatigue subscale, 56/100 on the emotional well-being subscale, 25/100 on the social functioning subscale, 10/100 on the pain subscale, and 25/100 on the general health subscale.
She had been prescribed pregabalin (Lyrica, Pfizer) in the past but discontinued its use due to intolerable side effects. She agreed to participate in an interdisciplinary pain management program biweekly for four weeks at UT Southwestern Medical Center, in Dallas. The program included physical/manual therapy, cognitive-behavioral therapy, meditation, biofeedback, and occasional use of laser therapy with a LightForce laser (LiteCure Medical) at 25 watts of power and a wavelength of 810 to 980 nm. She was also taking duloxetine (Cymbalta, Eli Lilly) 80 mg daily and acetaminophen 1 to 2 g per day.
Despite this multimodal treatment regimen, she reported no significant improvement in her fibromyalgia symptoms. She was also taking oral hydrocodone 5 mg four to five times monthly for severe discomfort from acute flares in her fibromyalgia symptoms.
Changes in Level of Pain With HILT
The patient consented to receiving a series of HILT sessions with the Phoenix Thera-Lase device. The first 42-watt treatment was administered bilaterally at the paraspinous region and at 10 tender (“trigger”) points located at the shoulder and hip regions. The designated body areas were treated with a series of 60-second treatments located approximately 4 to 6 inches apart over the symptomatic area. The initial session lasted about 40 minutes and was correlated with improvement in joint pain (reduced to 1-2 on the 11-point VRS), range of motion, mood, level of physical activity and quality of sleep.
The benefits lasted for approximately one week, during which the patient required no opioid analgesia. She reported her pain relief as a 7 on the 11-point VRS after the first treatment session. After one week, her pain returned to 50% of the pretreatment level.
Subsequently, the patient returned for an abbreviated HILT session using the same device at the same 42-watt power setting; the focus was the general region of the spine only. The session lasted about 30 minutes, and she reported initially excellent pain relief (with a pain relief score of 6 on the 11-point scale), but the beneficial effect lasted only four days.
The patient later underwent a 1-watt treatment with the Phoenix Thera-Lase device in the same paraspinous region, lasting about 30 minutes. This resulted in minimal improvement in her pain symptoms (pain VRS score of 5-6), and the duration of the effect was only two to three hours.
Finally, she received another 30-minute HILT treatment at the paraspinous region at 75 watts with the same device. The patient reported profound analgesia (pain VRS score was reduced to 0-1) lasting about 10 days.
Two weeks after this session, her fibromyalgia pain symptoms returned to greater than 50% of her baseline pain values; however, the patient had not required any opioid-containing analgesic medication for performing activities of daily living. This case strongly suggests that the power level of the HILT was a key factor in the magnitude and the duration of the analgesic effect. This case report was recently accepted for publication in Rheumatology International.
This case report suggests that the use of HILT at 42 to 75 watts of power at longer wavelengths—compared with lower HILT laser settings at wavelengths less than 1,000 nm—can produce more profound and longer-lasting beneficial effects than standard multimodal treatment protocols for fibromyalgia. Currently, Dr. White and his colleagues are conducting a double-blind, sham-controlled study at UT Southwestern Medical Center (ClinicalTrials.gov. Identifier: NCT02948634) using 42-watt HILT sessions for drug-resistant fibromyalgia.
“Although additional sham-controlled studies are clearly needed,” Dr. White said, “use of more powerful photobiomodulation laser therapy could potentially improve the lives of millions of patients suffering from the painful symptoms of fibromyalgia while also reducing their risk for long-term opioid dependence.”