Skin Resurfacing of Facial Rhytides and Scars with the 90-μs Short Pulse CO2 Laser

Abstract

Carbon dioxide lasers that produce either short pulses or scanned continuous beams have been used for skin resurfacing to improve wrinkles or scars. Using a high peak power, short pulse CO2 laser can produce clinically effective results with minimal thermal damage. To evaluate the effectiveness of skin resurfacing using the 90-microsecond pulse duration CO2 laser compared to other laser systems. Erythema, healing time, complications, and histological measurement of the depth of ablation and thermal damage per pass with this system were also assessed. Forty-one patients with facial rhytides and scars underwent resurfacing with a 90 microseconds pulse duration CO2 laser. Using patient survey, patients were evaluated for effectiveness of therapy, healing time, and complication rates. Comparisons of histologic and clinical findings were made with different short pulse CO2 lasers. Healing time, duration of erythema, and post-operative pain were less with the 90 microseconds pulse CO2 laser than with the 900-microsecond dwell time and 950-microsecond pulse duration lasers, while effectiveness was comparable. Complications were few with the 90-microsecond pulse laser, including three patients (9.1%) developing hyperpigmentation. One pass with the 90-microsecond pulse duration CO2 laser produced 100 microns of ablation with 17 microns of thermal damage. Ablation and damage were additive so that, by six passes, ablation depth was 350 microns and depth of thermal damage was 63 microns. This thermal damage is less than that reported with lasers having a longer pulse duration or dwell time with comparable depths of vaporization. Treatment with the 90-microsecond pulse duration laser results in a more rapid healing time and shorter duration erythema. The clinical improvements in wrinkles and sun damage were comparable. The 90-microsecond pulse duration laser provides an effective, predictable, and safe means of improving facial rhytides and scars.