Analysis of diode, argon, and Nd: YAG peripheral iridectomy in cadaver eyes

We compared semiconductor diode, neodymium (Nd): YAG and argon laser iridectomies performed in 14 cadaver eyes using Miyake videographic, histologic and scanning electron analysis. We found that the diode laser created an iridectomy in < 10 applications in blue, hazel and brown irides using 1000-1200 mW over 0.5 seconds. In hazel and blue irides the argon laser created iridectomies at parameters similar to the diode, but required multiple low energy burns in brown irides. Scanning electron microscopy showed pigment epithelial loss with the diode and Nd:YAG laser, and heaped up epithelium at the iridectomy site with the argon laser. Nd:YAG laser had the greatest iridectomy size. This study suggests a possible clinical advantage of diode versus argon laser iridectomies in reduced applications in brown irides and in preventing postoperative pigment occlusion. However, diode laser demonstrated no definite advantage over Nd:YAG laser.