Nonablative laser treatment of facial rhytides : Cutaneous applications of lasers : dermatoly, plastic surgery, and tissue welding

The purpose of this study is to evaluate the safety and effectiveness of the New Star Model 130 neodymium:yttrium aluminum garnet (Nd:YAG) laser system for nonablative laser treatment of facial rhytides (e.g., periorbital wrinkles). Facial rhytides are treated with 1.32 μm wavelength laser light delivered through a fiberoptic handpiece into a 5 mm diameter spot using three 300 μs duration pulses at 100 Hz pulse repetition frequency and pulse radiant exposures extending up to 12 J/cm 2 . Dynamic cooling is used to cool the epidermis selectively prior to laser treatment; animal histology experiments confirm that dynamic cooling combined with nonablative laser heating protects the epidermis and selectively injures the dermis. In the human clinical study, immediately post-treatment, treated sites exhibit mild erythema and, in a few cases, edema or small blisters. There are no long-term complications such as marked dyspigmentation and persistent erythema that are commonly observed following ablative laser skin resurfacing. Preliminary results indicate that the severity of facial rhytides has been reduced, but long-term follow-up examinations are needed to quantify the reduction. The mechanism of action of this nonablative laser treatment modality may involve dermal wound healing that leads to long-term synthesis of new collagen and extracellular matrix material.