Commentary on: Photobiomodulation: The Clinical Applications of Low Level Light Therapy Free

In the article “Photobiomodulation: The clinical applications of low level light therapy,” ¹ the author extensively reviewed the literature and summarized the history, functions, clinical evidence, and current controversies surrounding the utilization of low-level light therapy (LLLT). LLLT, also known as photobiomodulation, is a fast-growing treatment strategy that employs photons at a non-thermal irradiance to alter biological activity.² Coherent light sources (lasers), non-coherent light sources (light-emitting diodes), or a combination of both are utilized. LLLT’s inception dates back to the 1960s, and since that time, the US Food and Drug Administration has deemed its power level low and safe enough for medical uses.³ Currently, LLLT has been utilized for treating various conditions, including skin aging, acne vulgaris, alopecia, and body contouring. However, as mentioned by the authors, a lack of regulation on the LLLT devices by the Food and Drug Administration regarding these therapeutic claims has allowed commercial exploitation. Additionally, although extensive pre-clinical research has been conducted on LLLT, clinical studies have produced inconsistent results due to too many variables and confounding factors (eg, wavelength, spatial coherence, pulse structure, fluence, irradiance and exposure frequency, etc.),⁴ therefore hindering the optimal application of this treatment in the clinical setting.

To bridge the laboratory findings with clinical applications, we investigated and attempted to define the role and value of LLLT. We have previously demonstrated the effectiveness of visible light, in the form of the He-Ne laser, in treating patients with segmental vitiligo, particularly in children with peri-orbital and peri-oral lesions. The effect is thought to be mediated by stimulation of melanocyte proliferation and migration as well as enhancement of primitive melanoblast differentiation.^5-8 We also noticed a normalization of cutaneous blood flow, measured by Laser Doppler flowmetry, in patients with segmental vitiligo after treatment with visible light (wavelength 635 nm). Subsequently, we demonstrated that the cutaneous blood flow profiles before and after visible light therapy may serve as a response predictive assay for patients with segmental vitiligo.⁵ This predictive assay helped to select the right patients to undergo LLLT for the vitiligo lesions. Future studies focusing on clinical application of LLLT must include establishment of specific protocols and treatment predictors. With the recent advances in artificial intelligence and big data analytics, appropriate studies incorporating these new approaches will likely establish the clinical roles of LLLT in the near future.

Disclosures

The authors declared no potential conflicts of interest with respect to the research, authorship, and publication of this article.

Funding

The authors received no financial support for the research, authorship, and publication of this article.

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