Ablative laser resurfacing: high-energy pulsed carbon dioxide and erbium:yttrium-aluminum-garnet.

The development of the short-pulsed high-energy carbon dioxide laser in the mid 1990's led to the emergence of laser skin resurfacing. Used in the continuous mode, the CO(2) laser can cut and coagulate simultaneously. Used in the pulsed mode, the CO(2) laser is a powerful tool for epidermal ablation in many different contexts both therapeutic and cosmetic. Both the CO(2) and Erbium YAG lasers emit light in the infrared spectrum. Energy is preferentially absorbed by intracellular water creating rapid heating and vaporization of tissue. Because of the wavelength of the Er:YAG laser (2940 nm) more closely approximates the absorption peak of water (3000 nm) the target chromophore than the CO(2) laser (10,600 nm) nearly all of the energy is absorbed in the epidermis and papillary dermis yielding superficial ablation and less underlying thermal damage. The advantages, disadvantages, and applications of each type of laser resurfacing will be discussed. Despite proven efficacy, the public acceptance of laser resurfacing has declined with the emergence of new laser systems that cause dermal remodeling without ablating the overlying epidermis dramatically reducing recovery time. In the absence of blinded comparison studies, it remains unclear whether the clinical results of the newer 'nonablative' laser systems compare with their ablative predecessors.