Altering cellular function using low level, non-thermal LED light is called photobiomodulation (PBM) or low-level light therapy (LLLT), and is a medical treatment modality of increasing clinical importance.1 Because of the combination of high degree of penetration in skin2 and absorption by respiratory chain components, light in the spectral range from 600 to 1300 nm is useful for promoting wound healing, tissue repair, and skin rejuvenation.3–5 In contrast to traumatic ablative (e.g., laser resurfacing) and non-ablative (e.g., intense pulsed light [IPL]) skin rejuvenation modalities that induce secondary tissue repair by causing controlled damage to either the epidermis or the dermis, PBM is atraumatic, and bypasses the initial destructive step by directly stimulating regenerative processes in the skin. Its action mechanisms encompass increased cellular proliferation, migration, and adhesion.6 Important cell types for skin and tissue regeneration are fibroblasts, keratinocytes, and immune cells (mast cells, neutrophils, and macrophages), which can be stimulated using specific wavelengths with significant tissue penetration properties.7
A Controlled Trial to Determine the Efficacy of Red and Near-Infrared Light Treatment in Patient Satisfaction, Reduction of Fine Lines, Wrinkles, Skin Roughness, and Intradermal Collagen Density Increase
