Late histopathological findings of neodymium:YAG laser iridotomies in humans.

We studied three sector iridectomy specimens from three patients who had undergone neodymium:YAG (Nd:YAG) laser iridotomies 3 to 5 years earlier for treatment of imminent angle closure glaucoma. The specimens were obtained during cataract extraction and were examined by light and transmission electron microscopy. In all iris specimens, the edges of the iridotomy sites consisted of loosely arranged melanocytes, fibrocytes, and vessels. In the iris stroma, there were numerous pigment-laden cells. The iris vessels appeared to be intact; there were no fibrinous aggregates, no inflammatory response or scarring, nor any signs of proliferation of the iris pigment epithelium. Our findings suggest that in humans, iris wound healing after Nd:YAG laser iridotomy occurs without induction of fibrous scars or proliferation of the iris pigment epithelium. This indicates that there is no tendency toward late closure of the iridotomy sites.