In cynomolgus monkeys, resting total outflow facility was unaltered 1 and 6 or more months after ciliary ganglionectomy (CG) or postganglionic ciliary neurectomy (PCN). Intraocular pressure (IOP) was decreased in the denervated eye 1 week and 1 month after surgery, but returned to normal after 6 or more months. Although baseline facilities were comparable in CG/PCN and fellow control eyes 6 or more months after surgery, even maximal intracameral doses of pilocarpine did not increase outflow facility in previously denervated eyes, while a normal facility increase occurred in fellow control eyes. However, both previously denervated and fellow control eyes exhibited a large facility increase to both submaximal and greater than maximal intracameral doses of eserine.