Anne Hendren Coulter, Ph.D.

Phototherapy, healing with light, may have been one of thefirst natural therapies. The Greeks used the sun to treat ill-ness. Vitamin D, acquired through exposure to the sun,

can increase bone strength. Simulated sunlight in the form ofbright light has been shown to reduce psychologic stress. Today,researchers are trying to reproduce light’s healing propertiesusing devices such as light emitting diodes (LEDs) or low-levellasers (LLLs). Harry T. Whelan, M.D., Bleser Professor of Neurol-ogy, and director of the Photobiology Research Laboratory, Med-ical College of Wisconsin (Milwaukee, WI), a physician usingsuch devices, asks: “After years of poison (pills) and knives(surgery) in medicine, wouldn’t it be nice to have something gen-tle, like light, to heal by enhancing our normal biochemistry?”

Niels Finsen, M.D. (1860–1903), a Dane who won the 1903Nobel prize in Physiology or Medicine, may well have been thefirst to investigate light as medical therapy. Dr. Finsen used light,crudely filtered with lenses and lamps, to treat lupus vulgaris. Inhis clinical study, 50 percent of 800 treated cases were cured.While this successful medical treatment was what won him theNobel Prize, perhaps his most significant contribution to futuremedicine was that he “blazed the trail for scientific phototherapyand the curative use of rays other than those contained in ordi-nary light.”1

The trail that Dr. Finsen opened has been untraveled forsome time. Not until the late 1960s did another physician, Hun-garian Endre Mester, M.D. begin to experiment with pho-totherapy. At that t ime, he exposed diabetic ulcers to anear-infrared (NIR), low-level, 50mW, 632.8 nm helium-neon(He-Ne) laser. The ulcers gradually healed. The medical com-munity scoffed at him when he reported his findings. Therewere no scientific studies to back his findings. No doubleblinded, placebo-controlled studies backed his results withhard science. Like acupuncture, Chinese herbs, and other typesof adjunctive medicine, this form of light therapy was believedto be nothing more than “snake oil,” a treatment with anecdo-tal success.

Light in Many Forms

Low-level laser therapy (LLLT) investigation slowed to an avo-cation, an interesting hobby in the medical community, because,of course, the treatment was regarded as having no physiologicbasis. In recent years, the ready availability of the LED has facili-tated a new wave of investigation into both LED-based and LLL-

based therapies. The differences between them are noteworthyand may be important for determining the optimal medicalapplications of each.

LEDs and lasers both radiate light at various wavelengths,including therapeutic doses in the range from 810 nm to 850 nm.However, lasers emit coherent, narrow line width light, (e.g., 810nm ± 5 nm), which means that they can be directed at very spe-cific “absorption” bands of the intended molecular absorbingcenters, which are called chromophores. LEDs emit incoherentlight with broader linewidths (e.g., 505 nm ± 35 nm).

According to Luis De Taboada, vice president of Researchand Development at Photothera Corporation (Carlsbad, Califor-nia), “narrow line widths could make a difference on the overallefficiency of the process if the target chromophores have nar-row absorption lines that can be more closely matched bylasers. The role coherence may play in the effect is still unclear.If the target has a broad absorption linewidth and tissue pene-tration is not an issue, perhaps the LED might be the more effi-cient [device].”

From a different perspective, that of energy and power intensi-ty, Dr. Whelan notes that the LED is likely to be useful in themedicine of the future, because the “thin beams of light pro-duced by lasers make it difficult to achieve consistent powerintensities and energy densities. . .LED arrays can, therefore, bemore easily studied in terms of energy density (Joules/sq cm)and power intensity (milliwatts/sq cm).”

Military Light: The Laser Emitting Diode

LEDs were originally developed by the National Aeronauticsand Space Administration (NASA) to grow plants in space. Asresearch into the biologic applications of LEDs progressed, itbecame apparent that LEDs can emit light at wavelengths thatcan reduce brain tumors in children. Dr. Whelan, a pediatric sur-geon, secured NASA funding to test the device for treating pedi-atric brain tumors. In the course of testing the surgical propertiesof LEDs, Dr. Whelan began other studies: One used the devicesto treat mucositis in children and another used LEDs to treat dia-betes-related wounds in mice.

In addition, the Defense Advanced Research Projects Agency(DARPA) supplied the LED venture with another group of testsubjects—enlisted men—to determine the device’s usefulness asan aid to wound healing. The DARPA funded development of anLED array housed in a small hand-held device that that was sentwith soldiers on a submarine to test whether individual marinerscould apply the device to their own wounds, thereby acceleratingthe process of wound healing.

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Let There Be Light–and Healing

The pediatric mucositis study has yielded the most definitiveresults supporting the clinical applications of LEDs. At theMedical College of Wisconsin, Dr. Whelan and his colleaguesshowed that healing of oral lesions associated with chemothera-py was facilitated by use of the NASA LEDs2 in 32 children,ranging in age from 3 to 23 years old. The children served astheir own controls to determine the effectiveness of the LEDtreatment. One side of each child’s mouth was treated with anLED, while the other was not. The patients’ pain was reducedby nearly one half following LED treatment. Remarking on theimportance of this study, Dr. Whelan said: “Now children whohad lesions that caused enough pain to impair food intake canactually eat again.”

Numerous other animal studies are being conducted withthe LEDs. Raymond J. Lanzafame, M.D., M.B.A., F.A.C.S.,director of the Laser Center at Rochester General Hospital(Rochester, New York) is also investigating the feasibility ofusing the NASA LEDs for wound healing in the general popu-lation. With the intention of adding LED treatment to the arma-mentarium of noninvasive tools for wound healing, the studywill gather 100 patients, randomize them, and test them overseveral years.

Lasers in Medicine: Exploring More Uses

Despite his clinical successes, Dr. Whelan is the first to cau-tion that all LED applications are still experimental. Lasers,however, are already approved for clinical use and for certainapplications. Because lasers are available for physician use,investigation into other clinical laser applications has beenongoing for some time.

MicroLight Corporation of America’s (Missouri City, Texas)laser, for example, received Food and Drug Administration(FDA) market clearance in 2002 to sell the company’s laser deviceto U.S. medical doctors, physical therapists, hospitals, clinics,

occupational therapists, ath-letic trainers, and chiroprac-tors for treatment of carpaltunnel syndrome (CTS). Thedevice, which emits light at830 nm, is now used by vari-ous prac t i t ione rs for th isapplication. Explains Micro-Light founder and president,Mike Barbour , “ the la se ra p p e a r s t o b e e f f e c t i v ebecause it encourages actualcel l repa ir . While surgeryworks in only 20 percent ofcases,” he continues, “lasertherapy works in as many as70 percent of CTS cases.”

MicroLight is preparing tomarket its device to veteri-narians to treat certain equine diseases and plans to conductadditional human clinical studies on the possible use of the com-pany’s laser device for treatment of such human health problemsas arthritis, tendonitis, and sports injuries.

A British company, Thor International Ltd. (London, England)recently received FDA clearance for its LED and laser probes.The company’s devices are currently used to treat painful joints,nerves, lower-back pain, and sciatica, and for dental work, prin-cipally in animals. The laser probe appears to be particularly use-ful for veterinary applications because of its shorter treatmenttime. Animals who may not cooperate with prolonged medicaltreatment can be treated quickly.

The Photothera Corporat ion is evaluat ing a number ofapplications for its low level laser. The company is awaitingFDA approval of use of its device for treating tendonitis and,eventually, for alleviating muscle and tendon pain. Jackson

ALTERNATIVE & COMPLEMENTARY THERAPIES—DECEMBER 2003 323

Harry W. Whelan, M.D., Photobiol-ogy Research Laboratory, MedicalCollege of Wisconsin.

Definition of LasersThe laser (originally an acronym for light amplification stimulated emission of radiation) has been used in many medical applications. Lasers

produce thin beams of coherent light and have narrow bandwidths, facilitating their ability to interact resonantly with tissue. It is the laser’shigh intensity in combination with one biologically consistent wavelength that makes the laser an efficient cutting tool. As the light passesthrough skin, it is absorbed by the tissue based on color and frequency. The laser’s use is determined by the channel through which it isshone—gas, solid-state, or semiconductor. The laser’s cutting ability is determined by the fluence or concentration of energy and the deliverysystem used, specifically, a lens, waveguide, or fiber.

So-called “surgical lasers,” those that vaporize skin, cut through it superficially or cut skin at greater depths, are used principally bysurgeons, ophthalmologists, and other specialists to accomplish procedures that might otherwise be performed with a scalpel. Lasers are asurgical tool of choice by surgeons who wish to take advantage of these devices’ cauterizing capability, reduction in postoperative pain (aprincipal advantage of the low-level laser), and subsequent reduction in hospital stays.

These are not the lasers used in alternative ways; they are the lasers that are and have been accepted as surgical tools. Interestingly enough,however, they have not stimulated the interest that many physicians once thought they would because they are expensive, they eliminate thesurgeon’s tactile connection with diseased tissue, and their subtleties of light/tissue interaction have not seemed important or comprehensibleto many physicians.

Gas lasers, the ruby laser and the helium neon (He-Ne) laser, two of the first lasers used in medicine were those that were first used forlow-level laser therapy (LLLT). Because they can be directed at a particular spot, these low-level lasers were found to be useful for debridingthe edges of wounds.

That lasers produce coherent light is biologically important. Coherent light appears to have some specific advantages in interacting withtissues and organs, such as the heart or brain, that are found deep in the body. Laser applications, based on their types and wavelengths, aresummarized in the box entitled Laser Wavelengths and Applications.

Streeter, M.D., the company’s founder and chief scientific offi-cer, also noted that LLLTs can be used clinically for more com-plex procedures.

Lightening Patients’ Pain

Lasers and LEDs hold promise as useful devices for homeboundpatients and people with restricted mobility. In a recent study,Katie Lagan, D.Phil., and colleagues at the University of Ulster atJordanstown (North Ireland) showed how lasers were effective insuch a situation. Dr. Lagan gave an 8-week treatment with a con-

tinuous-wave diode (GaAIAs) laser to a 51 year-old woman withchronic venous ulceration.3 Soon after treatment started, thepatient observed a reduction in her pain and, by the end of treat-ment, the investigator noted a one-third reduction in wound size.

Dr. Lagan’s study indicated that LLLT appears to be “an effec-tive treatment for patients suffering venous ulceration.”3 Perhapsmore importantly, she suggests, is that because of its success, thetreatment may help reduce the pain of venous ulceration that is a“major health problem in the elderly and a drain on the resourcesof health services everywhere.”3

Ultimately, both lasers and the LEDs will be small enough andinexpensive enough to allow consumers to use them at home toheal their own wounds. This is already possible with LEDs.

Major LEDs for Home Treatment

LED arrays, when placed within safe housing, are classified bythe FDA as “infrared heating devices” and are used to treat chronicpain. Several companies are selling the devices, which range in pricefrom $200 to $1000, to practitioners and consumers for this applica-tion, (see box entitled Manufacturers of Light-Therapy Devices).

Light-Force Therapy, (Elizabeth, Colorado) sells three LEDarray devices that are appropriate for use by consumers andpractitioners in human and veterinary settings. Detailed instruc-tions describe how to get optimal benefits from the devices,which are sold for reducing acute and chronic pain associatedwith such conditions as arthritis; tendonitis; fibromyalgia; muscleand joint pain; and muscle spasm, stiffness, and soreness.

BioScan (Placitas, New Mexico) has another device, which, likethe Thor probes, has been used on animals since the 1970s.Nadine Donahue, the company’s founder and chief executive

324 ALTERNATIVE & COMPLEMENTARY THERAPIES—DECEMBER 2003

Laser Wavelengths and Applications

Laser name Wavelength Medical Use

Crystalline laser mediumKTP/532 532 nm Leg vein treatmentRuby 694 nm Tattoo and hair removalAlexandrite 755 nm Bone cut, hair removalNd:YAG 1064 nm Tumor coagulationHo:YAG 2130 nm Surgery, root canal, lithotripsyEr:YAG 2940 nm Dental drill, laser peelingTi:sapphire Tuneable Two-photon PDTSemiconductor lasersInGaAIP 630–700 nm BiostimulationGaAIAs 780–820–870 nm Biostimulation and surgeryGaAs 904,905 nm PDT, dermatologyGas lasersExcimer 193,248,308 nm Eye, vascular surgeryArgon 350–514 nm Dermatology, retinopathyCopper 578 nm DermatologyHe 633,3390 nm BiostimulationCO2 10,600 nm Dermatology, surgery

Source: Tuner J, Hode L. Laser Therapy. Grangesberg, Sweden: Prima Books, 2002:26. Used with permission.

Top: Hand-held Dio LFT 3000 LEDarray device and hand-held LFT9000 LED array device, both manu-factured by Light-Force Therapy,Inc., Elizabeth, Colorado. Bottom:Hand-held QUANTUM WARP 10LED array device manufactured byQuantum Devices, Inc., Barneveld,Wisconsin, delivers infrared lightenergy to a patient’s wrist.

officer, has been acquiring experience in the use of veterinarypain-relief devices that have established track records, for humanapplications. The BioScan system can be used on humans andanimals to ease chronic pain. “The effectiveness of the device,”she says, “suggests that we have, at last, an alternative to the pill,needle, knife progression.”

Quantum Devices, Inc. (Barneveld, Wisconsin), the companythat provides Dr. Whelan with the LED arrays for his experi-ments, expects to have approval to sell its hand-held device bythe end of 2003. This hand-held device, which runs on AA batter-ies, is the one that was used in the wound-healing experimentsby the submarine crew. To investigate the device’s portabilityand simplicity of use further, Dr. Whelan and his research groupexpect to take the device to Brazil to treat a family with a heredi-tary optic neuropathy, Leber’s disease. If the device does make adifference, he says, “we will leave it with them so that they cantreat themselves.”

Major Laser Devices for Home Treatment

Lasers have also been introduced that can be used in the home.Margaret Naeser, Ph.D., Lic.Ac., Dipl.Ac., department of neurolo-gy , Boston Universi ty School of Medicine (Boston, Mas-sachusetts), using a small hand-held device, has shown that laseracupuncture is effective for treating stroke victims who haveparalysis on one side.4 Treating seven patients who had strokes,by applying a low-level NIR laser (gallium aluminum arsenide)on various acupuncture points (shallow points on the hands andface and deeper points on the arms and legs) of the subjects, 20–40seconds, 2–3 times per week, for 3–4 months, Dr. Naeser foundthat 71.4 percent of the patients experienced improvement. Thetreatment is “especially desirable. . .[because]. . .the patient can betrained to treat him/herself at home using an inexpensive 5 mWred-beam diode laser pointer. At a beam diameter of 1 mm, such alaser produces an intensi ty of about 6000 Wm-2, an intensi tywhich is six times larger than the value of the solar constant—theintensity of the solar irradiation above the clouds (1000 Wm-2).”4

Mechanisms of Healing with Light

The most difficult step toward approval of any indication forlight therapy is finding the elusive “mechanism of action,”without which many practitioners will not take a new treat-ment seriously. Early work by a Russian investigator, Tiina I.Karu, Ph.D., of the Institute of Laser and Informatic Technolo-gies, Russian Academy of Sciences, Troitsk, Moscow Region,and more recent work by Dr. Whelan’s group in Wisconsin,suggest possible mechanisms to explain the mystery of lighthealing.

Current thinking holds that light works at a basic cellular levelthat encourages the body to use its innate healing capabilitiesthus facilitating “natural” healing.

Cells need basic energy forms, such as sugars or fats, to pro-duce adenosine triphosphate (ATP), the energy currency, that willuse oxygen to complete this metabolic reaction. Light and cellularactivity facilitate this reaction. As a result, scientists reasoned that

ALTERNATIVE & COMPLEMENTARY THERAPIES—DECEMBER 2003 325

Laser therapy and low-level laser therapy wound treatment studies areongoing at the Laser Center at Rochester General Hospital, whereresearchers are actively investigating multiple wavelengths and treat-ment parameters. Photograph by Jeff Blackman, Manager of VisualCommunications at Rochester General Hospital.

Manufacturers of Light-Therapy DevicesBioScan

45 Dusty Trail DrivePlacitas, New Mexico 87043Phone: (800) 388-2712e-mail: nadine@bioscanlight.com

Light-Force Therapy650 East Walnut StreetP.O. Box 306Elizabeth, CO 80107-0306Phone: (888) 259-9996Fax: (303) 646-3052Or contact: Ms. Kim Peterson, PresidentPhone: (303) 646-3300, extension 15

MicroLight Corporation of America2935 Highland LakesMissouri City, Texas 77459Phone: (281) 433-4648Or contact: Michael M. Barbour, Presidente-mail: m.barbour@sbcglobal.net

Quantum Devices, Inc.P.O. Box 100112 Orbison StreetBarneveld, WI 53507Phone: (608) 924-3000e-mail for sales information: qdisales@quantumdev.comFax: (608) 924-3007

Thor International Ltd.Caer SidheChiltern RoadAmershamBuckinghamshire HP6 5PHEnglandPhone: 01494-434-656Fax: 01494-431-481Web site: www.thorlaser.com

laser or LED light could provide the light energy. Dr. Karu madethe first connections between light and cellular activity.5

In a summary of her work beginning in the early 1990s,5 Dr.Karu suggested that the monochromatic red light of a laser (oran LED) could cause a photobiologic reaction that would stimu-late ATP production. For monochromatic red to NIR radiation,she suggested, cytochrome c oxidase, an enzyme that assistselectron transfer in the mitochondria (a stage in the respirationcycle), could be one possible photoreceptor.5 Margaret T.T.Wong-Riley, Ph.D., in Dr. Whelan’s DARPA group, has actuallyproven this, by demonstrating enhancement in the cytochromec oxidase activity of brain cells with LED treatment.6

Because ATP production encourages cell proliferation andbecause accelerated wound healing requires new cells, scientistshave concluded that oxygen and light energy, in this case provid-ed by the monochromatic red light, may be the reason that LEDsand lasers heal wounds.

Dr. Karu’s suggestion that light therapy may act on the mito-chondria to effect healing, has been substantiated further by J.T.Eells, Ph.D., in a study of rat blindness, as part of Dr. Whelan’sDARPA-funded LED project. In a recent issue of the Proceedings ofthe National Academy of Sciences U S A,7 Dr. Eells described thestudy. LEDs were shined on rats that had been injected to thepoint of intoxication with methanol, a substance that disrupts cel-lular mitochondrial activity and ultimately causes blindness. Theanimals who received the LED treatments had a significant recov-ery of rod and cone function. These results suggest that the use ofLED treatment “may enhance recovery from retinal injury. . .inwhich mitochondrial dysfunction is postulated to play a role.”7

Light at the End of the Tunnel

According to Dr. Whelan, the FDA has determined that DARPALED-technology poses a nonsignif icant risk, because it makeshigh-intensity NIR light, but no heat. Used to accelerate woundhealing, it is unlikely to cause thermal burns, which prohibit otherLED/light-sources from use in many medical conditions.

The jury is still out on healing with LEDs and lasers. Scientistshave been performing bench research to prove the safety and effi-cacy of both types of devices in many applications. At present, thetwo devices appear to have different capabilities and characteris-tics. LEDs are far less expensive than lasers. LEDs seem to improveeyesight. Lasers seem to heal tendons. Light therapy, generally,appears to promote healing of both physical and psychologic dis-ease. LEDs and lasers appear to heal pathologic disease. In vitaminD–deficient areas or places with prolonged winter darkness, brightlight seems to ameliorate seasonal affective disorder. It could bethat all of these devices have possible roles in promoting goodhealth. Or, again, it could be that none of them is necessary. Couldit be, as Ron Ignatius, president of Quantum Devices Inc., sug-gests, “that we were born to be naked, that our bodies need only tobe exposed to more photons to remain healthy”?

References

1. Online document at: ww.nobel.se2. Whelan HT et al., NASA light-emitting diodes for the prevention oforal mucositis in pediatric bone marrow transplant patients. J Clin LaserMed Surg, 2002;29:319–324.3. Lagan KM. A case report of low intensity laser therapy (LILT) in themanagement of venous ulceration: Potential effects of wound debride-ment upon efficacy. J Clin Laser Med Surg 2000;18:15–21.4. Naeser M. Laser acupuncture to treat paralysis in stroke patients, CTscan lesion site study. Am J Acupuncture 1995;23(1):13–28.5. Karu TI. Cellular Mechanisms of Low-Power Laser Therapy (Photo-biomodulation). Online document at: www.laserhealthsystems.com[undated].6. Wong-Riley MTT, Bai X, Buchmann E, Whelan HT. Light-emittingdiode treatment reverses the effect of TTX on cytochrome oxidase in neu-rons. NeuroReport (Neurochemistry) 2001;12:3033–3037.7. Eells JT, Henry MM, Summerfelt P, Wong-Riley MT, Buchmann EV, KaneM. Whelan NT, Whelan HT. Therapeutic photobiomodulation for methanol-induced retinal toxicity. Proc Natl Acad Sci U S A 2003;100:3439–3442.

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326 ALTERNATIVE & COMPLEMENTARY THERAPIES—DECEMBER 2003