INFLUENCE OF THE PULSE DURATION ON PHOTOABLATION WITH THE ER-YAG LASER IN OCULAR TISSUE (CORNEA AND SKLERA)

After photoablation in corneal and scleral tissue with the Er:YAG laser, two zones of thermal damage can be detected: The first zone (about 3 mum thick) consists of thermally denaturated debris. The second zone (about 30 mum thick) shows a slightly more intense staining (H&E) compared to the non-influenced tissue. Variation of laser pulse duration between 100 mus and 1300 mus does not influence the extention of these two thermal damage zones. Furthermore, ablation rate and ablation volume remain nearly constant within this range of pulse durations. These data were obtained by histology (H&E staining) and with a recently published silicon cast replica method. All experiments have been performed on corneas and scleras of pig eyes.