Adrenergic drug effects on aqueous outflow facility following ciliary muscle retrodisplacement in the cynomolgus monkey.

Cynomolgus monkeys with untouched, totally iridectomized, or totally iridectomized and ciliary muscle-disinserted eyes underwent two-level constant-pressure perfusion of the anterior chamber to determine the effect of intracameral mock aqueous humor, l-epinephrine bitartrate (10 microgram), l-norepinephrine bitartrate (10 microgram), ergotamine tartrate (1 and 20 microgram), and angiotensin II amide (1 and 100 microgram) on total outflow facility. Ergotamine and angiotensin both tended to decrease facility. Epinephrine and norepinephrine significantly increased facility, approximately 25% and 40%, respectively, beyond the effect of mock aqueous in all three types of eyes. The percentage increases in facility produced by epinephrine and norepinephrine were virtually identical in disinserted and nondisinserted eyes and were independent of starting facility in the individual eyes. Our results prove that the epinephrine- and norepinephrine-induced facility increase in cynomolgus eyes is not mediated by the iris or ciliary muscle and suggest that the increase in total facility is due largely to increased facility across the trabecular meshwork.