Nonablative laser treatment of facial rhytides

摘要

Abstract: The purpose of this study is to evaluate the safety andeffectiveness of the New Star Model 130neodymium:yttrium aluminum garnet (Nd:YAG) laser systemfor nonablative laser treatment of facial rhytides(e.g., periorbital wrinkles). Facial rhytides aretreated with 1.32 micrometer wavelength laser lightdelivered through a fiberoptic handpiece into a 5 mmdiameter spot using three 300 microsecond durationpulses at 100 Hz pulse repetition frequency and pulseradiant exposures extending up to 12 J/cm$+2$/. Dynamiccooling is used to cool the epidermis selectively priorto laser treatment; animal histology experimentsconfirm that dynamic cooling combined with nonablativelaser heating protects the epidermis and selectivelyinjures the dermis. In the human clinical study,immediately post-treatment, treated sites exhibit milderythema and, in a few cases, edema or small blisters.There are no long-term complications such as markeddyspigmentation and persistent erythema that arecommonly observed following ablative laser skinresurfacing. Preliminary results indicate that theseverity of facial rhytides has been reduced, butlong-term follow-up examinations are needed to quantifythe reduction. The mechanism of action of thisnonablative laser treatment modality may involve dermalwound healing that leads to long- term synthesis of newcollagen and extracellular matrix material. !41