Fundamental Laws of Laser Therapy: Understanding the Principles of Laser Treatment

Laser therapy has revolutionised medical and aesthetic treatments, offering a range of benefits for various conditions. The efficacy of laser therapy is based on several fundamental laws that govern its application. In this blog, we will explore the fundamental laws of laser therapy and their significance in understanding the principles behind laser treatment.

1. Fundamentals of Laser Therapy – Law of Photobiology

The Law of Photobiology states that light, particularly laser light, can stimulate biological processes within the body. This principle forms the foundation of laser therapy, as laser light interacts with tissues and cells to produce therapeutic effects. The specific wavelength and energy of laser light determine its ability to penetrate tissues and activate cellular processes.

Citation: Karu, T. (2010). The Science of Low-Power Laser Therapy. Amsterdam: Elsevier.

2. Fundamental Laws of Laser Therapy – Law of Selective Photothermolysis

The Law of Selective Photothermolysis states that specific targets within the body can selectively absorb laser light based on their unique characteristics, such as colour or chromophore concentration. By adjusting the wavelength and pulse duration of the laser, it is possible to target specific structures, such as hair follicles or pigmented lesions, while minimizing damage to surrounding tissues.

Citation: Anderson, R. R., & Parrish, J. A. (1983). Selective photothermolysis: Precise microsurgery by selective absorption of pulsed radiation. Science, 220(4596), 524-527.

3. Law of Thermal Relaxation Time

The Law of Thermal Relaxation Time states that the time it takes for a target tissue to cool down after laser exposure is proportional to its size and thermal properties. This law is essential for determining the optimal pulse duration and repetition rate of the laser to ensure effective treatment without causing excessive heat buildup or damage to surrounding tissues.

Citation: Grossman, M. C., Dierickx, C., Farinelli, W., Flotte, T., & Anderson, R. R. (1996). Damage to hair follicles by normal-mode ruby laser pulses. Journal of the American Academy of Dermatology, 35(6), 889-894.

4. Law of Photochemical Reactions

The Law of Photochemical Reactions states that laser light can trigger specific biochemical reactions within cells. This includes the activation of cellular processes, such as collagen synthesis, cell proliferation, and modulation of inflammatory responses. The wavelength and energy density of the laser are crucial factors in determining the desired photochemical reactions for therapeutic outcomes.

Citation: Chung, H., Dai, T., Sharma, S. K., Huang, Y.-Y., Carroll, J. D., & Hamblin, M. R. (2012). The Nuts and Bolts of Low-level Laser (Light) Therapy. Annals of Biomedical Engineering, 40(2), 516-533.

 

Understanding the fundamental laws of laser therapy is essential for healthcare professionals and practitioners to optimise treatment outcomes and ensure patient safety. These laws provide insights into the mechanisms by which laser light interacts with tissues and cells, leading to therapeutic effects. By adhering to these principles, laser therapy can be effectively utilized across a wide range of medical and aesthetic applications, offering patients enhanced results and improved quality of care.