Transscleral neodymium-YAG cyclophotocoagulation. A histologic study of human autopsy eyes.

Transscleral cyclophotocoagulation was performed with a neodymium-YAG laser in the free-running mode (20-ms pulses) on eight human autopsy eyes. Variables studied were laser beam position and angle, defocusing, and pulse energy. Based on gross and histologic evaluation of the treated eyes, a tangential beam placed 1.0 to 1.5 mm behind the limbus, with maximum defocusing and an energy setting of approximately 8 J, appears to provide the optimum probability of damaging the ciliary processes.