Histological evaluations following 1,064‐nm Nd:YAG laser resurfacing

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background and Objectives</jats:title><jats:p>The long pulse 1,064‐nm Nd:YAG laser is used clinically to decrease rhytid formation. The dermal level at which this change occurs has not been established. This study attempts to answer these questions using a porcine skin model.</jats:p></jats:sec><jats:sec><jats:title>Study Design/Materials and Methods</jats:title><jats:p>Non‐randomized prospective experimental trial involving the domestic piglet treated serially with the long pulse 1,064‐nm Nd:YAG laser.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Collagen formation occurred at the level of the reticular dermis. After one laser treatment, a significant level of collagen formation was induced in the reticular dermis compared to controls. The greatest gain was observed after four laser treatments. Energy levels of 20, 30, 40, and 50 J/cm<jats:sup>2</jats:sup> were evaluated. Although not statistically significant, 30 J/cm<jats:sup>2</jats:sup> had the greatest effect on collagen formation. However, at 50 J/cm<jats:sup>2</jats:sup>, marked ablative changes to the epidermis were observed.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>The long pulse 1,064‐nm Nd:YAG laser induces collagen formation in the reticular dermis in porcine skin. Lasers Surg. Med. 33:126–131, 2003. © 2003 Wiley‐Liss, Inc.</jats:p></jats:sec>