Cryosurgical treatment of the eyelids and lacrimal drainage ducts of the rhesus monkey. Course of injury and repair.

Freezing injuries were produced on the eyelids and lacrimal drainage systems in ten rhesus monkeys. The instrumentation produced both single and double freezing cycles at tissue temperatures of -30 and -60 degrees C. The extent of injury and the course of repair were evaluated by clinical observation and by histologic examination of tissue specimens removed at intervals up to three months after freezing. Both cryosurgical techniques produced necrosis of the tissues, but injury was less with single freezing cycles at -30 degrees C. The course of repair was favorable. Even at the three-month observation period, when healing was complete, there was minimal-clinical or histologic evidence of canalicular obstruction or other periocular complications.