Fractional photothermolysis for skin rejuvenation.

BACKGROUND Fractional photothermolysis has become an important laser modality in management of a number of skin conditions and photoaging. The authors describe the scientific basis of fractional photothermolysis, report on most of the available devices, discuss their clinical uses and techniques, and attempt to decipher their relative efficacy. METHODS The authors reviewed as best as possible all fractional lasers currently approved by the Food and Drug Administration for distribution into the United States. Laser wavelength, means of delivery, depth of penetration, and special features were collated. RESULTS Nine fractional lasers were evaluated. Main differences in outcome were related to type of laser wavelength. In general, scanning technologies are faster and more precise. Deeper injuries result in more collagen remodeling. Variations in laser wavelengths, depth of injury, type of delivery system, consumables, and architecture of the fractionated laser light are important considerations when evaluating fractional lasers. Little scientific research comparing the injury, healing, and outcomes of the various fractional lasers is available. CONCLUSIONS Fractional photothermolysis represents a breakthrough in laser treatment for a wide array of skin problems. The safety profile has been improved over conventional ablative lasers, and the range of skin types and treatment areas have been expanded. Unlike full-surface flat beam resurfacing, fractional resurfacing damages specific microtreatment zones within the target area. Nonablative fractionals do not achieve results similar to those of the fractional ablative lasers, but certain conditions may respond better to nonablative fractional treatments. More data are needed on the comparative effects of the various types of lasers and their best indications.