Shining a Light on Wound Healing: How LED and LASER Therapies Transform Recovery

The healing of wounds is a critical aspect of healthcare, but not all wounds respond favorably to conventional treatments. As a result, researchers have explored innovative strategies to expedite the healing process and improve patient outcomes. One such approach gaining attention is low-power light therapy, which employs light devices like Light Emitting Diodes (LED) and Light Amplification by Stimulated Emission of Radiation (LASER). Although the therapeutic benefits of LASER have been known since the 1960s, LED therapy emerged only in the 1990s. This blog post aims to explore the biological effects of LED on wound healing, identify optimal LED parameters for wound treatment, and compare LED with LASER therapy. Understanding Wound Healing and Its Challenges Wounds, characterized by disruptions in body tissue continuity, can result from various physical, chemical, and mechanical traumas or underlying medical conditions. As life expectancy increases, the incidence of cutaneous wounds in adults has also risen. The treatment of wounds involves preventive measures, medications, and physical therapies, but challenging wounds often require innovative approaches. Shedding Light on Low-Power Light Therapy Low-power light therapy, known as photobiomodulation, has emerged as a promising approach in wound healing. It utilizes light devices like LASER and LED to apply specific light wavelengths to the affected tissue. However, conflicting results in the literature and questions about the equality of biological effects promoted by LED and LASER have sparked controversies. Unraveling the Biological Effects of LED on Wound Healing A comprehensive review of 68 studies (48 on LASER, 14 on LED, and 6 on both) shed light on the biological effects of these light therapies. Both LED and LASER demonstrated similar effects, including reduced inflammatory cells, increased fibroblast proliferation, stimulation of collagen synthesis, angiogenesis, and granulation tissue formation. Comparing LED and LASER Parameters To optimize the therapeutic effects of light therapy, the study investigated the critical parameters of LED and LASER. These parameters primarily include wavelength and dose. Both LED and LASER studies used wavelengths within the red and near-infrared spectrum, where light penetration in tissues is maximum. Doses up to 5 J/cm2 showed the most significant biological effects, following the Arndt-Schultz curve, indicating that very low and very high doses were less effective. How Light Interacts with Biological Tissues The effectiveness of light therapy depends on how the tissue absorbs the energy. While the exact primary reactions of light on photoreceptors inside mitochondria are not entirely understood, studies suggest that cytochrome c oxidase plays a crucial role. Absorption of light by cytochrome c oxidase leads to a cascade of secondary photobiological reactions, resulting in increased cellular metabolism, cell membrane permeability changes, and DNA and RNA synthesis. LED vs. LASER: The Coherence Debate One significant difference between LED and LASER is coherence. LASER light is coherent, meaning its waves have the same frequency, direction, and phase, while LED light lacks coherence. However, studies showed that LED therapy can be just as effective as LASER therapy, indicating that coherence is not a prerequisite for photostimulation or photoinhibition. The reviewed studies affirm the effectiveness of phototherapy using LED and LASER for wound healing. Both therapies demonstrate similar biological effects, highlighting the importance of defining optimal parameters, including wavelength and dose. Although LED lacks coherence, it still proves to be an effective therapeutic resource. With further clinical studies, LED and LASER therapies can revolutionize wound healing and offer better treatment options for challenging wounds, ultimately improving the quality of life for many individuals.