Abstract
Topical administration of the tricycic antidepressant compound protriptyline, 5-( 3-methylaminopropyl)-5H-dibenzo (a,d) cycloheptene hydrochloride, to the cornea of conscious rabbits and monkeys caused pupillary dilatation and a decrease in intraocular pressure. This response could be prevented either by sympathetic denervation of the eye or by i.v. injection of the alpha adrenergic receptor blocking agent, phenoxybenzamine. The administration of protriptyline, either topically or systemically, increased the sensitivity and duration of the response of the iris and intraocular pressure to norepinephrine and sympathetic stimulation. Analysis of the intraocular dynamics by manometric procedures in anesthetized rabbits indicated that the decrease in intraocular pressure induced by protriptyline was associated with a decrease in the outflow resistance and the rate of aqueous humor formation. In normal human subjects protriptyline induced pupil dilatation and a small pressure fall, which were associated with an increase in outflow facility and a decrease in the rate of aqueous humor formation. An ocular, hypotensive response to topically applied protriptyline was observed in four of eight patients with open-angle glaucoma.
Footnotes
- Received March 5, 1968.
- Accepted May 30, 1968.
- © 1968 by the Williams & Wilkins Co.
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