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CHAPTER OBJECTIVES
At the end of this chapter, the learner will be able to:
Define the terms laser, photobiomodulation, and chromophores.
Explain the effects of low-level laser on healing of a chronic wound.
Develop safe and appropriate application parameters for low-level laser therapy for the treatment of chronic wounds.
Select specific patient indications that may be appropriate for the use of low-level laser therapy in wound management.
Identify precautions and contraindications for the use of low-level laser for wound healing.
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Laser, an acronym for Light Amplification by Stimulated Emission of Radiation, is a special form of electromagnetic energy that is located within the visible or infrared regions of the electromagnetic spectrum.1 Unlike ultraviolet C (UVC) that has scientific evidence to support its use in wound management, laser therapy lacks scientific evidence at this time, specifically related to wound healing.2–4 Although low-level laser therapy (LLLT) is used in many countries to promote wound healing, laser therapy is not currently approved by the FDA for wound management and is still considered an experimental treatment by most insurance companies in the United States.3,5 Research on the effects of LLLT on wound healing has produced conflicting results due to inconsistency in treatment parameters used in various studies. If the proper LLLT parameters are not selected, the effectiveness of LLLT is reduced and can lead to negative treatment outcomes. These conflicting results, as well as a limited understanding of the biochemical effect of LLLT, contribute to the slow advancement of laser therapy for wound healing in the United States.6 This treatment, as with UVC, should only be performed by providers with expertise in the use of therapeutic technologies who rely heavily on research and evidence to determine the impact of therapeutic technologies on human tissue. The research on the impact of LLLT on wound healing does show promise for laser therapy having a specific role in wound management in the future.7
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Because the average power of low-level lasers (or cold lasers) does not create an increase in tissue temperature, low-level lasers are the lasers of choice for wound treatment, and are classified as Class 3B/IIIb lasers.1,8 Monochromatic light emitted from low-level lasers falls within the red visible or infrared wavelengths on the electromagnetic spectrum, between 600 and 1200 nm, as shown in FIGURE 20-1. The following three distinct properties of light are required characteristics of LLLs and are shown in FIGURE 20-21:
Coherent: Photons that make up the light travel in a straight line.
Monochromatic: Photons that make up the light have a single wavelength and therefore a single color.
Collimation: Light is concentrated in one well-defined area.
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