Ablation of Cultured Cells With the ARC Dodick Laser Photolysis System to Prevent Posterior Capsule Opacification

Abstract

Abstract: : Purpose:There is still no method for prevention of posterior capsule opacification (PCO) after cataract surgery. The purpose of this study was to investigate the potential of Dodick Laser Photolysis in PCO prevention by testing the ablative characteristics of laser induced shockwaves in various cultured cells. Methods:Murine 3T3 cells and human tenon fibroblasts were grown to confluence on plastic (Falcon 6mm dishes). For cell ablation a commercially available laser photolysis system (A.R.C. Laser GmbH, Eckental–Forth, Germany) in conjunction with a specially designed measurement stand was used. The area of cell ablation generated by the shockwave of a single laser pulse was measured on the plastic surface. The relation of ablation area and the following parameters was determined: Laser pulse energy (7 or 10 mJ), distance between laser tip and cell culture (1 – 6 mm), angle of incidence of the shockwave to the surface (45° or 90°). Results:The laser induced shockwave led to a nearly round shaped ablation with relatively sharp margins in cultured 3T3 cells as well as in human tenon fibroblasts. Inside the ablation zone a complete polishing of the plastic surface was found. Increasing the distance between laser tip and cell culture led to a smaller ablation area. At 6mm distance no more cell ablation was detectable. A shockwave, which was generated by 10 vs. 7 mJ pulse energy, resulted in a mean ablation area of 10.05 vs. 4.25 mm² (1mm distance between tip and 3T3–cells, 90° angle of incidence). The ablation area was larger at 90° angle of incidence of the shockwave than at 45°. Conclusions:The shockwave generated by the ARC Laser Photolysis System permits reproducible ablation of cultured cells on plastic. Short distance between tip and cells, high pulse energy and perpendicular angle of incidence leads to an increase of ablation zone. Our study indicates the potential of intraoperative capsular bag polishing for prevention of PCO in the future.

Keywords: posterior capsular opacification (PCO) • laser • cataract