Semi-Automated method of analysis of horizontal histological sections of skin for objective evaluation of fractional devices

Background and Objective The treatment of skin with fractional devices creates columns of micro‐ablation or micro‐denaturation depending on the device. Since the geometric profiles of thermal damage depend on the treatment parameters or physical properties of the treated tissue, the size of these columns may vary from a few microns to a few millimeters. For objective evaluation of the damage profiles generated by fractional devices, this report describes an innovative and efficient method of processing and evaluating horizontal sections of skin using a novel software program. Materials and Methods Ex vivo porcine skin was treated with the Lux1540/10, Lux1540 Zoom and Lux2940 with 500 optics. Horizontal (radial) sections of biopsies were obtained and processed with H&E and NBTC staining. Digital images of the histologic sections were taken in either transmission or reflection illumination and were processed using the SAFHIR program. Results NBTC‐ and H&E‐stained horizontal sections of ex vivo skin treated with ablative and non‐ablative fractional devices were obtained. Geometric parameters, such as depth, diameter, and width of the coagulated layer (if applicable), and micro‐columns of thermal damage, were evaluated using the SAFHIR software. The feasibility of objective comparison of the performance of two different fractional devices was demonstrated. Conclusion The proposed methodology provides a comprehensive, objective, and efficient approach for the comparison of various fractional devices. Correlation of device settings with the objective dimensions of post‐treatment damage profiles serve as a powerful tool for the prediction and modulation of clinical response. Lasers Surg. Med. 41:634–642, 2009. © 2009 Wiley‐Liss, Inc.