Shock-wave effect on anterior segment structures following experimental neodymium:YAG laser iridectomy

The short-pulse laser may prove superior to the argon laser in producing noninvasive iridectomies. Little is known of the effects of the laser shock-wave on anterior segment structures adjacent to the iris. To investigate this question, iridectomies were produced in two owl monkeys using a neodymium (Nd):YAG laser and tissues were evaluated by light microscopy and scanning and transmission electron microscopy. For purposes of comparison, one eye received an iridectomy produced by an argon laser. Results indicate that while clean iris colobomas can be produced with a well-focused Nd:YAG laser, its shock-wave affects tissues in both the trabecular meshwork and corneal endothelium if the iridectomy is located within 0.8 mm of the limbus. No damage to the trabecular meshwork or corneal endothelium was evident after the argon laser iridectomy.