Both light and RF are forms of electromagnetic energy, but the mechanisms of action utilized by each are quite different. The mechanism of action for light-based devices is based on “selective photothermolysis”. When photons are absorbed by skin chromophores (i.e., water, melanin, blood, etc.) the light energy is transformed into heat. When tissue heat reaches different levels, hyperthermia, coagulation or vaporization can result. When RF energy is applied to the skin surface, rapidly oscillating electromagnetic fields cause movement of charged particles within the skin and the resultant molecular motion generates heat.
RF devices interact with tissue in a different way than light-based devices. With RF energy, the electrical current emitted interacts with tissue to generate a current of ions which incurs resistance as it passes through the tissue. This resistance—also called “impedance”—generates heat in proportion to the amount of impedance. Tissues with high impedance are heated more than tissues with low impedance. The mechanism of action for inducing dual layer skin rejuvenation is comprised of a two stage process.
The first phase of the skin rejuvenation process is the immediate skin response to both the mechanical and thermal injury resulting from the fractional RF energy delivery and the injury resulting from the micro-puncture of the skin. The selective delivery of RF energy to both the epidermal and dermal skin layers from the micro-electrodes stimulates immediate collagen contraction (shrinkage) and destruction through both mechanical and biochemical pathways. The first phase of treatment also results in tissue regeneration leading to the release of skin growth factors and triggering fibroblast proliferation.
The second phase of the process results in long term collagen remodeling and elastin formation leading to more youthful and beautiful skin appearance. The controlled thermal injury to the dermal layers results in the production of new collagen, elastin and hyaluronic acid for increased skin volume, elasticity and thickness. As a result of the energy delivered deep into the dermis, collagen remodeling via a controlled wound healing response occurs over time with associated neocollagenesis. Thus collagen remodeling also results in the highly desirable “skin tightening” that is observed with iFRAX treatments.