Photobiomodulation: An Enlightened Path Emerges

I was deeply honored to be selected as the keynote speaker for the 14th Annual Conference of the North American Association for Laser Therapy (NAALT) held in West Palm Beach, Florida, January 31–February 2, 2013. It was heartening to see the progress that NAALT has made, as evidenced by the large meeting attendance and the excellent quality of the presentations. This was further reinforced by the NAALT session that was held in conjunction with the 33rd Annual Conference of the American Society for Laser Medicine and Surgery on April 6 in Boston. Both meetings provided the audience with both the basic concepts and some of the cutting edge research in a number of disciplines. Mechanisms of action were explored and theories were presented and discussed.

The title of my presentation at the 2013 conference was similar to the title I have chosen for this editorial. My keynote address was focused on the case for photobiomodulation and some of the evidence and controversies in the science and clinical applications of photobiomodulation today. We considered the current status of photobiomodulation in mainstream medicine and whether the preponderance of evidence has reached the tipping point for wider adoption and use of these modalities. The modern therapeutic applications of so-called low-level laser therapy (LLLT) have been in use for >40 years. There is a growing body of evidence demonstrating the scientific basis for the photobiomodulation effect. ¹ Several systematic reviews and meta-analyses demonstrate positive results for clinical applications in pain management and wound healing. ^{1 –4} There is increasing interest in the potential applications of LLLT in neurologic disorders and injuries. ^{1,5 –9}

However, despite the growing body of evidence, it is clear that this discipline has not been embraced by the medical mainstream. Photobiomodulation is, at best, in the early adopters phase of the Rogers innovation diffusion timeline ¹⁰ rather than at the tipping point of adoption. Karu recently made a similar observation as she considered the concept that photobiomodulation might be considered as being equivalent to drugs in their use and effects. ¹¹ She noted that there is an expanding base of scientific evidence regarding the mechanisms of action for the photobiomodulatory effects observed in both clinical and research scenarios, and suggested that it is appropriate to equate the clinical application of these modalities as having similar efficacy to drugs.

This premise is of major importance, particularly as modern Western medicine relies on pharmacology and the use of a broad array of drugs to treat various clinical conditions, including the relief of pain. Other treatments that do not utilize pharmacotherapy are typically considered as being complimentary or alternative medicine (CAM) strategies. The current medical opinion is generally that such therapies are ineffective and without scientific proof or merit. It is clear that the pendulum has swung in terms of being willing to explore CAM as potential adjuncts or alternatives to classical medical management. This has undoubtedly been fueled by the ratcheting down on government expenditures for healthcare and healthcare-related research, and the transformation and evolution of the evidence-based medicine paradigm into one of attempting to promote cost effectiveness and comparative effectiveness research.

Such concerns are indeed important, particularly in the context of longer life expectancies, the tsunami of aging Baby Boomers reaching retirement age and consuming large quantities of healthcare, and the strain that expenditures for the same will place on personal and public finances. Both the medical and lay press are replete with articles describing changes in guidelines for big ticket and frequently performed screening procedures such as colonoscopy, Pap smears, prostate-specific antigen testing (PSA), and mammography. It is certainly appropriate to re-evaluate and refine practices as more evidence emerges, and it would be foolhardy to ignore the fact that there are, or should be, limits on the consumption of healthcare resources.

We must also be vigilant and be willing to carefully evaluate the context of the changing recommendations and to consider the differing impact that these decisions make from the perspective of the individual patient, the employer, and payers, and the government and society as a whole. The importance of this is underscored by the famous cases of gas tank fires in the Ford Pinto in the late 1970s. ¹² In this case, a low cost fix to an engineering problem was subjected to a cost benefit analysis that examined the expenses related to payments necessitated by death or injuries resulting from the defective part versus the cost of the repair. Executives effectively placed a dollar value on a human life and argued that it was not cost effective or profitable to conduct the repairs, despite the fact that the cost could be transferred to consumers. ¹² The take-home message is that the individual places a different value on his or her life and quality thereof as compared with the valuation of the cost for that life as viewed from the perspective of governmental payers and society as a whole. It is important to act responsibly and ethically as we attempt to balance the needs and wants of the individual versus those of society as a whole. The question that we as readers of this journal and as scientists and clinicians must answer is how do we expand the knowledge base and applications of photobiomodulation in the present climate of cost containment and renewed skepticism of therapies that are viewed as being outside of the current medical mainstream?

We continue to make progress in defining the mechanisms by which the photobiomodulation effects occur, and we continue to apply these technologies and principles to a growing array of clinical conditions. However, controversies exist as regards optimal wavelengths, parameters, and devices. Some of these result from a lack of thorough study of the various options in a controlled and rigorous fashion and/or the inability to conduct well-matched clinical trials. Some of the controversy is steeped in tradition and dogma, and is to some degree fueled by the need for manufacturers and practitioners to attempt to differentiate themselves from their competitors in the marketplace.

There is no question that the interaction of photons with cells is a necessary and essential condition for photobiomodulation. Absorption and transduction of this energy must occur, and cellular molecules and structures are capable of absorbing energy at various wavelengths. We must recognize the fact that not all cells and tissues respond to phototherapy. It is also important to understand that one size does not fit all when it comes to determining the dose or time course of treatment for different tissues and scenarios. These features are arguably the same as one might consider when evaluating a drug, its optimal dosing strategy, and its best uses. Admittedly, phototherapy can be useful in instances in which traditional pharmacotherapy is not helpful or is contraindicated. However, these strategies are not a panacea.

Overselling the attributes and benefits of photobiomodulation, whether preached by clinician, scientist, manufacturer, or patient must be avoided. Our path forward is best paved with careful research and methodical testing of parameters and treatment paradigms, coupled with honest evaluation of the results, both positive and negative. This balanced approach requires our constant vigilance and patience. The enlightened path becomes brighter as we proceed forward and continue to build responsibly on our collective efforts.