Dye-enhanced diode laser photothermal ablation of skin

Background: Near-infrared diode lasers are promising new Light sources. However, their applications for rapid and precise removal of tissue is limited because their radiation is poorly absorbed by most tissue. Objective: Our purpose was to determine the interaction of diode laser radiation with tissue by topically applying absorbing dye to enhance laser-tissue interaction and to examine the ability of this approach to create superficial and localized thermal effects in skin. Methods: Immediate and long-term responses of guinea pig skin to low-power (3 to 5 W x 1 sec) diode laser (805 nm) irradiation in conjunction with indocyanine green as a dye were studied. Tissue response was characterized on the basis of gross and histopathologic analysis of biopsy specimens taken at different times. Results: The observed depths of thermal damage with dye were greater than those produced by diode laser used alone at higher power settings (10 W x 1 sec). Conclusion: Interaction of diode laser radiation enhanced by topical application of dye causes localized superficial thermal effects in skin. This may offer a new modality in the treatment of superficial lesions.