Effect of pilocarpine on intraocular pressure in ocular hypertensive subjects

In normal subjects, ocular administration of pilocarpine results in initial elevation of IOP succeeded by a fall. We have now examined the effect of pilocarpine on IOP in nontreated ocular hypertension. Our results demonstrate that the initial hypertensive phase is absent in these patients and that the subsequent hypotensive phase is more marked than in normotensive eyes. It is suggested that in normal eyes IOP is regulated by two opposing cholinergic effects, and imbalance the two may lead to ocular hypertension (or hypotension).