Neodymium:YAG laser iridectomy and acute cataract formation in the rabbit.

The Q-switched Neodymium:YAG (Nd:YAG) laser in the single pulse mode was used to perform iridectomies in pigmented and albino rabbits. Seventy-one iridectomies were attempted. Seventy-six percent (54/71) of these were patent at the time of enucleation. Iridectomy closure was not noted during the 24-day study period. Lenticular damage was not detected in any case. Patency rates in pigmented (70%) and albino (78%) irides were similar. Energy levels of 6 mJ or greater resulted in a higher rate of patency. Settings below 6 mJ were associated with more significant bleeding and had a low rate of success. The histology of acute Q-switched Nd:YAG laser iridectomy is characterized by fragmentation of the stroma and wide dispersion of the pigment epithelium. Minimal healing occurs with retention of normal iris architecture without atrophy or fibrosis. Results indicate that this procedure can be performed with minimal operative complications and without a tendency for closure.