THOR Photobiomodulation Therapy Products & Training

Last October a systematic review on LLLT for neck pain was written by Kadhim-Saleh et al and published in the British Journal of Sports Medicine. They report that the evidence for LLLT in neck pain is inconclusive. The paper criticises the 2009 Lancet review by Roberta Chow & Bjordal et al on LLLT for non-specific neck pain claiming their review was more stringent. Well you have to read the rebuttal Bjordal shot back to the journal editor revealing the weakness, errors and fundamental flaws in the work of Kadhim-Saleh et al

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LLLT Systematic reviews with meta-analysis are hard to do for all sorts of reasons:

1) LLLT has had a lot of different names (cold laser, laser biostimulation, photobiomodulation, low intensity laser laser therapy, LEDT,  etc) so the literature search is hard (see my post on this from 2008, recently updated)

2) The authors need to have an advanced knowledge of the pathology in question.

3) The authors need to have an advanced knowledge of LLLT too, particularly the matter of irradiation parameters and dose*

4) Then the meta-analysis requires a high degree of competence with medical statistics

* So we should not be surprised when someone who looks at a broad range of interventions for a pathology with limited knowledge of LLLT struggles (and often fails)  to stratify the data by effective irradiation parameters (wavelength, power, beam area, irradiance, pulses), dose (time, energy, fluence), treatment location, number of treatments and interval between treatments.

It may be that LLLT is not a suitable intervention for the pathology in question but if LLLT appears to be effective sometimes and not others then you have to stratify the data in the way that others have done to discover that there may dose, dose rate (irradiance/power density) or other irradiation dependent effects.

The WALT guidelines go some way towards helping the reviewers in this regard though there are gaps due to lack of data, and even then there are mistakes in the original papers which makes writing those guidelines hard too.

I will get around to preparing a blog post on my extended version of the WALT guidelines which attempt to fill in the gaps based on extrapolation and first principles.

In October a paper was published claiming that class IV laser is more effective than class 3B for oral mucositis.  The authors attempt to con the reader by asserting they used a “standard” 3B laser protocol, but instead they set up a weak protocol delivering just 15% of the recomended energy in order to make a “class IV laser” product appear more effective.

As you know the marketing  claim for class IV devices is that they have more power so should go deeper, should reduce treatment time and should be more effective, well guess what, most of their power is using wavelengths that do not penetrate (970-980nm) [1]. All the evidence on dose consistently shows  that over treatment reduces effectiveness [2][3], treatment times are longer due to the scanning technique [4] and when you look at the small handful of clinical trails done with class IV lasers they use the same irradiation parameters used by 3B lasers anyway![4]

Such  misinformation is intended to direct a doctor / therapist away from what is proven to work in favour of something more expensive. If you you see a manuscript with “HILT” or “class IV laser” in the title watch out for the marketing spin.

I wrote a letter to the journal editor. I will post a link when it is published.