Effects of a cyclic AMP phosphodiesterase inhibitor, 8'-pivaloyloxymethyl ester of griseolic acid, on aqueous humor dynamics in rabbits.

The mechanism by which pivaloyloxymethyl (POM) ester of griseolic acid (GA), a potent cyclic AMP-phosphodiesterase inhibitor, lowers intraocular pressure (IOP) in albino rabbits was studied. The rate of aqueous flow, measured by fluorophotometry, was significantly lower in GA POM ester-treated eyes (2.36 +/- 0.24 microliters/min) than in control eyes (3.02 +/- 0.24 microliters/min). Topically applied GA POM ester did not alter tonographic outflow or uveoscleral outflow. No differences in aqueous humor protein concentrations between GA POM ester-treated and control eyes were observed. It was thought that the GA POM ester lowered the IOP by decreasing the aqueous inflow. Topical application of this compound caused no inflammatory response in the eye or changes in the blood aqueous barrier.