CLINICAL EFFECTS OF LASER THERAPY

Primary Response 

Primary response is elicited when photons emitted by the laser reach the mitochondria and cell membranes of underlying cells such as fibroblasts, where photonic energy is absorbed by chromophores and is converted to chemical kinetic energy within the cell. Chromophores absorb photons with wavelengths between 700 and 1100 nanometers (NIR, or near infra-red), with those in the 808nm and 980nm wavelengths being the deepest penetrating.   

Secondary Response 

Secondary reactions lead to the amplification of the primary actions. A cascade of metabolic effects results in various physiological changes at the cellular level—such as changes in cell membrane permeability. Calcium is released from the mitochondria resulting in changes of intracellular calcium levels. This stimulates cell metabolism and the regulation of signaling pathways responsible for significant events required for tissue repair such as cell migration, RNA and DNA synthesis, cell mitosis, protein secretion, and cell proliferation.  

Tertiary Response 

Tertiary effects are induced at a distance from the cells in which the secondary events occur. Energized (irradiated) cells communicate with each other and with nonirradiated cells through increased levels of cytokines or growth factors, along with correlating electromagnetic energy field interactions. This intercellular communication on the cellular biochemical and electromagnetic energy field levels results in an increase in (ATP) Adenosine Triphosphate production, enhanced immune response with the increased activation of T-lymphocytes, macrophages, and number of mast cells, an increase in the synthesis of endorphins, and a decrease in bradykinin results in pain relief, and a general increase in the energy levels of targeted tissues, as well as additional beneficial interactions. While tertiary effects can be least predictable because they rely on intercellular interactions and vary according to tissue factor variables, they can be most profound and have a major effect on beneficial targeted tissue interactions.