Selective photothermolysis in skin by using subcutaneous optical fibers

Background and Objective: Vascular selective photothermolysis has been show n to be effective in treating hypertrophic scars. Performing selective phot othermolysis on the vasculature deep within thick scars requires new method s for delivering laser energy. It is the objective of this study to model t he use of subcutaneous fiber optics to perform selective photothermolysis i n skin as a possible aid in the treatment of thick scars. S tudy Design/Materials and Methods: A Monte Carlo simulation was performed t o study the expected region of vascular necrosis in a two layer skin model when 585-nm radiation is delivered into the dermis by means of subcutaneous optical fibers. Results: The extent of vascular necrosis is independent of fiber diameter f or a fixed total energy. A fiber penetrating barely below the epidermis dec reases the maximum epidermal fluence by more than an order of magnitude rel ative to a superficial beam. Using four fibers simultaneously can significa ntly increase the depth of vascular necrosis, Conclusions: Small diameter fibers are optimum if the maximum fluence toler able in the dermis is not a limiting factor. Shallowly inserted fibers can significantly decrease epidermal damage to dark-skinned patients undergoing laser (C) 2000 Wiley-Liss, Inc.