Superficial wounding model for epidermal barrier repair studies: Comparison of erbium:YAG laser and the suction blister method

Background and Objectives Wound-healing studies use mainly mechanical methods for wound induction, which are laborious and difficult to standardize. Objective of this study was to evaluate the Erbium:Yttrium-Aluminium-Garnet (Er:YAG) laser method as a model of epidermis ablation on human skin in vivo and to compare the quality and healing rates of Er:YAG laser and suction blister (SB) wounds. Materials and Methods Er:YAG laser and SB wounds were made on the forearms of 10 healthy volunteers. Post-wounding measurements including wound surface area (WSA) from photographs, wound depth from 3D volume analysis, trans-epidermal water loss (TEWL), laser doppler blood flow (LDBF), and optical coherence tomography (OCT) imaging were made daily over 7 days. Biopsies were taken on Days 4 and 7. Results 3D analysis showed laser wounds to be shallower and more uniform in depth than SB: 54 +/- 14?mu m versus 140 +/- 102 mu m, respectively, with histology demonstrating complete epidermal removal using SB. SB wounds were more variable in size with a WSA of 0.47 +/- 0.24?cm2 compared to 1.17 +/- 0.14?cm2 for laser wounds. Healing rates were similar in both groups, as measured by TEWL, LDBF, and WSA. OCT imaging on Days 34 revealed new epidermis below the fibrin clot, similar to histology, and a visible stratum corneum on Day 7, but no apparent epidermal hyperplasia in contrast to histology. Conclusion Compared to the SB model, Er:YAG laser achieved rapid standardized epidermal ablation, which despite morphological differences, was similar in terms of epidermal regeneration/barrier formation. Lasers Surg. Med. 44: 525532, 2012. (c) Wiley Periodicals, Inc.