How to Write a Good Photobiomodulation Article

The renaming of the journal as “Photobiomodulation, Photomedicine, and Laser Surgery” ¹ has provided a good opportunity to remind authors of some important points to be borne in mind when writing an article in the general area of photobiomodulation, whether that be an original experimental study, a case report, a review, or a perspective article.

The first point to be addressed is terminology. After decades of confusion and floating around in a veritable muddle of acronyms and self-invented terms, such as low-level laser therapy (LLLT), low-level light therapy, cold or soft laser, low power or low intensity this, that, or the other, the field has come together to agree on the use of the terms “photobiomodulation” or “photobiomodulation therapy”, depending on whether a scientific process or a therapy is being discussed. ^2,3 The reasons for this choice are threefold. First, there was no agreement on what the term “low” actually meant. Second, the growing realization that noncoherent light sources such as light-emitting diodes (LEDs) could perform as well as lasers ⁴ meant that including the term “laser” was no longer appropriate. Third, the realization that many of the applications involved inhibition of biological processes, rather than the more usual stimulation, meant that the term “modulation” was more appropriate. Although authors can continue to use the widely accepted acronym “LLLT” occasionally in their articles, the acronyms “PBM” and “PBMT” should be the primary choice.

The next point to be addressed is parameter reporting. Nothing is more likely to raise the ire of commentators than what is perceived as inadequate reporting of parameters. In 2011, Jenkins and Carroll published an editorial ⁵ in the journal entitled “How to report low-level laser therapy (LLLT)/photomedicine dose and beam parameters in clinical and laboratory studies.” (NB: this was before photobiomodulation became the accepted terminology). In this publication the authors laid down an inclusive table of parameters that should be present in every experimental and clinical study of photobiomodulation (PBM) or photobiomodulation therapy (PBMT). Although it is possible that this table was somewhat overinclusive, this was a good initial approach to introduce standardized parameter reporting. However, the editorial staff at the journal have now agreed on a new table for reporting parameters (Table 1).

For custom-made or homemade devices, enough information should be given to allow others to reproduce the device. For review and perspective articles, it is unrealistic to expect a parameter table for every single report of PBM included in the survey, but the most important parameters (laser or LED, wavelength, power, power density, fluence, energy, and number of sessions) should be given for each study mentioned in the text. If the authors of the article in question have not provided these details, then consideration should be given to omitting it.

The third point I would like to make is the following. The best PBM articles set out to address a clear scientific question or to test a clinical therapy. Far too often laboratory-based articles appear where the authors have selected some parameters to vary in their particular experimental model, such as wavelength, fluence, or power density, without any clear idea of what they expect to find. Even though they have taken care to confirm that their results are reproducible, and they provide statistically significant differences, they still often seem to be at a loss to explain their results. PBM results must make sense in the light of what is known about molecular and cellular biology.

Finally, a plea to authors is to keep abreast of the latest publications on the mechanisms of action of PBM. Although the classic articles of Tiina Karu such as Ref. ⁶ laid the groundwork for the role of cytochrome c oxidase and mitochondria in many PBM effects, a lot of new materials have been published since then. The role of nanostructured water and infrared light, and green and blue light-activated opsins are good examples.

The recent acceleration of interest in PBM and the steady increase in the number of articles submitted for publication suggest that not only the number of publications but also their quality should increase, if the subject is to be taken seriously by mainstream modern medicine. Photobiomodulation, Photomedicine, and Laser Surgery will continue to publish only the best articles in the field with the long-term goal of increasing the credibility of PBM and PBMT as a whole, while at the same time to increase the impact factor of the journal.