Evaluation of clinical, microscopic, and ultrastructural changes after treatment with a novel Q‐switched Nd:YAG laser

Abstract

Background: The Q‐switched Nd:YAG laser was among the first non‐ablative lasers to be used. High‐fluence photoacoustic Q‐switched laser treatments were shown to produce results akin to those seen with some ablative lasers. Previous low‐fluence, non‐thermal, Q‐switched Nd:YAG lasers produced almost no results. Objective: The purpose of this study was to evaluate a new combined photoacoustic/photothermal low‐fluence Q‐switched Nd:YAG laser in the treatment of facial photodamage. Methods: Ten individuals with photodamaged facial skin were enrolled in the study. Participants underwent six bi‐weekly full‐face treatments using a Q‐switched Nd:YAG laser (RevLite, HOYA ConBio, Freemont, CA, USA) at 1064 nm, with an 8‐mm spot size and fluence of 3.2 J/cm². Clinical improvement was evaluated through blinded investigator assessment of photographs obtained before and 3 months after the last treatment. Pre‐auricular biopsies, performed before and 3 months following the last treatment, were processed for light and electron microscopy and analyzed for evidence of treatment‐related changes. Results: Eight individuals completed the study with no serious or long‐term complications. Blinded evaluator assessment documented improvement in a variety of different aspects of photodamaged skin. Biopsy specimens revealed changes consistent with wound repair under light microscopy, while electron microscopy confirmed new collagen deposition. Conclusion: A novel combined photoacoustic/photothermal Q‐switched Nd:YAG laser can be used for non‐ablative photorejuvenation. In addition to clinical improvement, histological and ultrastructural changes consistent with new collagen deposition were noted.

• Lasers and light sources
• photorejuvenation