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More Lies and Subterfuge from the World of Class IV Laser Therapy

By Jan Tunér

The US laser manufacturer LiteCure (a.k.a. Companion/Pegasus for veterinary version) belongs to a group of laser manufacturers that confuse customers and let consumers pay a high price for something that they do not need. LaserAnnals has previously addressed the so-called Class IV lasers for LPT in general and in a few cases mentioned this particular culprit LiteCure. In this article, we will make a closer check on the credibility and ethics of this company.

Marketing is generally a way of stretching the truth or at least highlighting potential benefits of a product without mentioning the drawbacks. Not very ethical but more or less what consumers expect. Sheer lying is a bit different, and LiteCure uses blatant lies in its marketing. Let us see the first lie:

Lie #1. LiteCure originally claimed that 980 nm has a much better penetration than 808 nm, and that the very high output of their lasers improves the penetration. The illustration below is from their early attempts at marketing the supposed benefits of their device:

pegasus_old1

Anyone with some basic knowledge about tissue optics knows that 980 nm has a poor penetration due to absorption by water and lipids, and that 808 nm (the illustration actually states 880 nm, but this is not a commonly-used laser wavelength so we assume this was another error…) actually is in an optical window where penetration through skin is optimal. Using very high power with 980 nm doesn’t increase penetration considerably, but instead causes more light to be absorbed superficially more quickly, leading to heat generation. And LPT is not based upon heat but upon stimulation!

Knowledgeable scientists, experienced clinicians and other manufacturers were quick to criticise, however, and to call LiteCure out on this lie, and over time LiteCure has responded by adding the deeper-penetrating 810 nm wavelength to their products, and by modifying the image, as follows:

pegasus_new1

Although a step in the right direction, even this illustration is still misleading and, basically, incorrect: The effective depth of laser irradiation does not increase over time.

Further to that, the “effortless” non-contact technique causes considerable energy loss by reflection and backscatter – together, remittance, which has been measured at upwards of 80% from bare skin (Al Watban, 1996) – and up to 100% energy loss due to absorption within animal hair/fur.  This is hardly “efficient”!

The truth is the opposite to what their sales claims try to tell: A 0.5 W 808-810 nm Class 3B laser actually has a superior ability to penetrate into the body, whereas a 10.0 W 980 nm Class 4 has limited ability and also causes more problems with regards to heat generation. And, as the lower-powered Class 3B device may be applied in contact with the skin directly over the pathological tissue, and held steady for the necessary time to deliver the appropriate amount of energy, it is also significantly more efficient, accurate and safe.

The problem is that their consumer group is rather ignorant about LPT basics and swallow the bait. Fortunately for LiteCure, very high energies are bio-inhibitory and have a temporary pain relieving effect. This is an impressing effect when demonstrated. The downside of the procedure is that the needed reduction of an inflammatory process in inhibited and so is the body’s ability to regenerate itself. This is what is called “a sales trick”.

Lie #2. In its advertising material the LiteCure company writes: “World renowned Laser Therapy Experts, Jan Tunér and Lars Hode have indicated the advantages of high power laser therapy. The (research) literature supports the hypothesis that higher power density yields better clinical results.”

This is similar to the way the devil reads the bible. The above conclusion follows a part of our book where the remarkably low powered lasers on the Canadian market in the ‘90s is discussed. The vast majority of the lasers used were HeNe 1-2 mW and GaAlAs 5-30 mW. So the 400 mW lasers that had just arrived on the market at that time seemed to have a new potential – and they had.

Continued reading of our book reveals that high energies probably will have a better effect on pain conditions but probably not on superficial conditions such as wound healing. In fact, the discussion following the text about “high power” strongly modulates their usefulness.

This text appeared initially in the 2002 book “Low level laser therapy – clinical practice and scientific background”. In following versions of this book, the text has been modified and becomes more critical of extreme energies. And believe me, the next one will be even more critical, to avoid any misunderstandings.

Read my lips: Tunér and Hode do not recommend 15 W Class IV lasers, not even 5 W!”  

An appropriately configured and applied Class 3B device can do all that we need, and if you want to reach deep targets the 904 nm superpulsed GaAs is the best tool!

LiteCure type of science

Recently a LiteCure research paper on fibromylaglia (FM) was published:

Panton L, Simonavice E, Williams K, Mojock C, Kim JS, Kingsley JD, McMillan V, Mathis R. Effects of Class IV laser therapy on fibromyalgia impact and function in women with fibromyalgia. J Altern Complement Med. 2013 May;19(5):445-52.

FM is a devastating condition and LPT is probably a viable option to use, especially since other therapies are rather ineffective and life-long intake of painkillers not a viable option, with the side effects in mind. The study by Panton is obviously performed by a competent team of medical experts, but it seems they have “been taken for a ride” by the LiteCure company. The overall effect of the laser treatment was modest, but had some effects.

So let us have a look on this paper…

For the laser group, treatment was rendered utilizing a LCT-1000 (LiteCure LLC, Newark, DE) solid-state GaAlAs laser delivering a continuous-wave, dual-wavelength laser with 20% 810 nm, and 80% 980nm at 10 W. Each 56.45 cm2 treatment point was treated with laser at 10.63 J/cm2 and warm air utilizing a grid scanning technique to avoid overheating tissue. Participants were instructed to expect some warmth but that the treatment should not burn and to provide verbal cues if the treatment spots became excessively warm. Each treatment point was treated for exactly 60 seconds for a total of 600 J per point, for a total daily treatment dose of 4200 J. The dual wavelength was used for two reasons: (1) this is what is commercially available and (2) two wavelengths allow for treatment in patients with different skin colours since different melanin concentrations will absorb light differently. Both wavelengths are in the accepted therapeutic window. The sham treatment consisted of 60 seconds of warm air alone over the seven tender points.

Now, let us try to make some sense about this study:

a. The cause of FM is not known, but it is manifested by painful bodily points. If pain were a separate biological unit, smashing it with a sledge hammer might be useful. But there is probably more to it, like peripheral neural sensitisation and inflammation. 600 J (!) is given to each point and this is a very high and quite inhibitive energy. And a “point” is declared to be 56.45 cm2. This is rather an area. But by spreading out the light over a large area, the dose becomes 10.63 J/cm2. Such a dose appears to be reasonable, but the energy is not.

b. The paper says: Like the IIIB lasers, recently developed Class IV therapeutic lasers use diffuse light at wavelengths in a therapeutic window that allow penetration of the light deep into the tissue. True, but these lasers do not penetrate deeper than the Class IIIB/3B lasers, so this is a deliberately misleading statement. Further, Class IV/4 therapeutic lasers are not exactly “recently developed”: The defocused beams of Class IV/4 surgical lasers have been used for therapy for equally as long as Class IIIB/3B devices. And the first commercially-available dedicated Class IV/4 therapeutic lasers came on the market in Europe during the ‘90s – which, of course, contradicts the claims by LiteCure and others that Class IV/4 laser therapy is new improvement of Class IIIB/3B. As they are now, these earlier Class IV/4 therapeutic lasers  were very expensive and inefficient, and proved no more effective than the already-available lower-powered lasers, so their use did not flourish until the marketing machine took hold in the USA.

c. The paper says: This development has led to the use of Class IV lasers to treat a variety of conditions including skin lesions(24,25), acute soft-tissue injuries (26), and chronic pain syndromes (27) such as FM. In fact, the references 24-27 are not related to the use of “Class IV” LPT lasers at all! This is a technique used often by LiteCure and other marketers of high-powered Class IV therapeutic lasers, banking on the fact that the casual reader will not follow through and actually read the referenced studies.

d. The paper says: There are only a few studies that have used laser therapy to treat pain (16,17,27,37,38). What about 125 published RCTs? If changed to “FM pain”, this is a more valid statement. And one of the most frequently quoted papers on FM and LPT (Gür et al.) used 2 J per point and with better results.

e. The paper says: Studies suggest that Class IV lasers have a beneficial analgesic and anti-inflammatory effect in humans (47-50). No, they don’t! All four papers to which they’ve referred are on Class 3B!

f. Previous studies on FM and LPT have been using considerably lower energies, so the reason for increasing these by a factor 100 seems to have but one background: To prove the superiority of the manufacturer’s product. However, the clinical outcome of this paper was not better than those where is Class 3B lasers have been used.

And let’s address another niggling falsehood: There is no such thing as “Class IV technology”!! 499 mW is Class 3B, 501 mW is Class IV. This is no “technology”. Laser classification is simply related to the relative risk posed by the power, wavelength and distribution of the laser emission!

The manufacturers of the Class IV lasers used in LPT have sponsored a small number of clinical studies. They all contain considerable flaws and even lies and are far from convincing. But they do contribute to the general confusion and are an obstacle in the general acceptance of laser phototherapy.

As mentioned previously, a typical trick of the Class IV vendor is to make reference to Class 3B papers, with proper documentation of their own products lacking. This was the old trick of LED vendors in the ’90s. The LEDs have, in the meantime, created their own scientific groundwork and do not have to use sales tricks any longer.

You can stop reading here, but if you like, here is the actual text from the book that is supposed to recommend Class IV lasers:

Stronger = better?

The power output of therapeutic lasers has increased radically during the nineties. McKibbin reports that there were about 1800 therapeutic laser units in Canada in 1990. 22% of them were HeNe lasers with an output of 1 mW or less, 35% HeNe lasers with 1-2 mW, 13% 830 nm units with an output up to 5 mW, 3% 830 nm units with an output up to 30 mW, 26% GaAs units with an output of 5 mW or less, and 1% units in the 760-780 range nm with an output up to 30 mW.

Now in 2009, the situation is quite different. HeNe units are being replaced by stronger InGaAlP lasers up to 500 mW, GaAlAs units of 7 000 mW are on the market, and GaAs units of 100 mW and more are available.

Even though it is possible to attain some effects with a 1-2 mW laser, there is no doubt that with a laser 100 times stronger, it is much easier to achieve biostimulating effects, at least if one intends to use treatment periods of the same length. Power density is also very important!

The authors used to have certain misgivings about an “inflation” with respect to the output power of therapeutic lasers. One misgiving was, and still is, the obvious risk of eye damage. The need for protective glasses has previously been exaggerated, but is now becoming more important. Another misgiving is the lack of research in the field of “high-power” therapeutic lasers. So far, insufficient data have been published on these powerful lasers. For the moment, we must rely primarily on our own clinical experience. That experience, however, is so encouraging that it cannot be ignored, even with the lack of scientific support. It would appear that “high-powered” therapeutic lasers will be able to further expand the scope of laser therapy, especially in pain therapy.

The doses previously recommended for laser therapy still hold true, in a way. However, much of what we know about dosage is based upon wound healing studies. This is the field in which both stimulating and inhibiting doses have generally been observed. But a wound is superficial, and the superficial tissue will absorb most of the laser energy. So treating a condition in the inner ear through the bone behind the ear is quite a different matter. The dense bone behind the ear absorbs some 90% of the light energy. Skin and blood absorb another 5%. Thus, 100 J in contact mode means only some 5 J or less in the inner ear. For pain and inflammation in large joints, such as the knee, quite a few joules may be required on the surface before the actual target receives the energy needed.

Using the same amount of energy but with different energy densities will not necessarily trigger the same biological response. Kim [545] used 1.2 J in plastic and aesthetic surgery. The energy was delivered either by a 1000 mW or a 60 mW 830 nm laser (1000 mW × 1.2 sec or 60 mW × 200 sec). Both were effective, but the 60 mW laser was more effective in the initial period of wound healing, while the 1000 mW laser was more effective in the late period.

Are strong lasers better than weaker ones?

YES and NO. Output power should not be too low for its purpose. If the power is too low, it causes unnecessarily long treatment time in order to achieve the required total dose (see more about the dose in the next chapter). Also, if output power is too low, it could result in the power density being too low which is an important parameter in treatment. Nor should output power be too high for its purpose. If the power is too high, the light could burn tanned, coloured skin, tattoos or skin with dark hair. Furthermore, in most countries, there is a power limit of 500 mW (= 0.5 watt), above which the laser may be a Class 4 laser. If so, it usually means that it requires oversight by an MD or DDS, more safety measures, and significantly more regulatory control. Also, if the power is too high, it can result in unintentionally high doses which can give less good treatment results than necessary (see the Arndt-Schulz curve in the next chapter). And finally, time is also an important treatment parameter. Administering a certain number of joules over a certain area using a certain laser power during a certain time, may not give the same result as using a ten times stronger laser during one tenth of the time with unchanged optical configuration. Another way to say this is that the rule of reciprocity is not valid. Some laser companies claim that a Class 4 laser ‘by default’ is better than a Class 3B laser (4 is higher than 3, so it has to be better… right?). This is simply not true. The classification of lasers is a measure of eye hazard, nothing else. While defocused Class 4 lasers may well be used successfully in laser therapy, this does not have anything to do with the laser classification.

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