Lack of adherence to the laser dosage recommendations from the world association for laser therapy in achilles study.

A letter by Bjordal et al was published addressing the tendinopathy study published Tumilty et al. Entitled “Lack of adherence to the laser dosage recommendations from the world association for laser therapy in achilles study”, full text below.

Tumilty et al reported delivering 0.21J per point however the WALT recommended energy per point in Achilles’ tendinopathy is 2.7 to 4.0J, so the authors did not adhere to recommended parameters from WALT.

Tumilty et al disagree but provide and inadequate argument as to why they claim adherence. Yes the the power density good and the treatment time was good but the beam size was too small and consequently the energy was wrong.

This matter was acknowledged in their published paper but was buried in discussion section rather than being acknowledged in the abstract or materials and methods where they claimed adherence to the WALT guidelines.

Future systematic reviewers of LLLT for tendinopathies must be made aware that the claim that their trial adhered to WALT guidelines is false.

This paper will weaken the effect size of future systematic reviews so I am using my blog to help highlight the Bjordal letter for reviewers to find on the future. See below.

Lack of adherence to the laser dosage recommendations from the world association for laser therapy in achilles study.

Bjordal JM, Lopes-Martins RA

Bergen University College, Bergen, Norway.

We have read with interest the study by Tumilty et al,1 which discussed patients with Achilles’ tendinopathy treated with low- level laser therapy (LLLT). Tumilty found no significant effect from LLLT, which, in our opinion, is to be expected with the doses they used. Laser parameters can be a complicated matter and may be confusing for clinicians. In this study, the authors claimed that treatment was given according to the dosage recommendations from the World Association for Laser Therapy (WALT) (www.walt.nu/dosage- recommendations.html). We disagree, but acknowledge the authors’ efforts to comply with the WALT dosage recommendations for a suitable power density (<100mW/cm2). The energy dose delivered per point is incorrectly reported as 3J in the abstract and method sections, and as .21J in the discussion section. The latter low dose explains how the modifications on the laser probe reduced power density, but unfortunately, this also reduced the laser output from 100mW to 7mW, resulting in a delivered energy dose on the skin of only .21J per point and 1.26J per session. We have made our own calculations based on the authors’ description and measured the optical laser output at the drilled hole of .07cm2 in the pipe. This confirmed that the lowest reported dose (.21J per point) is correct. The WALT recommended dosage per point in Achilles’ ten- dinopathy is 2.7 to 4.0J, when inflammation is present, and 30% less when inflammation is under control. From the general rule that a typical therapeutic window is limited by `50% of the recommended dose per point, the therapeutic window for Achilles’ tendinopathy is 1.35 to 6.0J per point. Thus, the lower WALT limit is about 6 times higher than the dose used by Tumilty. Consequently, the conclusion that no effect was found “despite adherence to recommended parameters from the WALT guide- lines”1(p738) is incorrect. In our opinion, the study was significantly underdosed and therefore did not comply with the WALT guidelines

Reference

1. Tumilty S, McDonough S, Hurley DA, Baxter GD. Clinical effectiveness of low-level laser therapy as an adjunct to eccentric exercise for the treatment of Achilles’ tendinopathy: a randomized controlled trial. Arch Phys Med Rehabil 2012;93:733-9.

http://dx.doi.org/10.1016/j.apmr.2012.07.034

The Authors Respond

We are pleased to be able to respond to the comments by Bjordal and Lopes-Martins on our recent article. It is clear from the level of detail provided that the comments have been carefully considered, and of course there is a debate over laser treatment parameters, which is not uncommon within the field.

This notwithstanding, it is confusing to read some of the comments leveled at our work, because we feel the points raised were well rehearsed in the discussion section of our article. In particular, it would appear that our discussion of the apparent ambiguity of the WALT treatment guidelines, and of the importance of the 100mW/cm2 irradiance limit for superficial tendinopathies, has been overlooked.

We therefore stand by our conclusion that no effect was found, despite adherence to recommended parameters. This is clearly an area where further work is required.

Steve Tumilty, PhD

Centre for Physiotherapy Research, School of Physiotherapy, University of Otago, Dunedin, New Zealand

Suzanne McDonough, PhD

University of Ulster, Newtownabbey, Co Antrim, United Kingdom

Deirdre A. Hurley-Osing, PhD

University College Dublin, Belfield, Dublin, Republic of Ireland

G. David Baxter, DPhil

Centre for Physiotherapy Research, School of Physiotherapy, University of Otago, Dunedin, New Zealand

Arch Phys Med Rehabil 2013 Feb 94(2) 408

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=23351679

 

About James Carroll

Founder and CEO at THOR Photomedicine Ltd. About THOR
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