Experimental labyrinthotomy in monkeys by argon and carbon dioxide lasers

The horizontal semicircular canal of squirrel monkeys was irradiated unilaterally with either an argon or carbon dioxide laser. Postoperatively, there was a small but significant reduction in caloric-induced ENG responses to 45 degrees thermal stimulation. The principal morphologic effect of laser irradiation was a plug of fibrous tissue or new bone within the lumen of the lesioned semicircular canal.