Topical 8-bromo-cyclic GMP lowers intraocular pressure in rabbits.

The topical application of 8-bromo-3'-5'-cyclic guanosine monophosphate (8BrcGMP) produces significant decreases in intraocular pressure (IOP) in rabbit eyes. Maximum effects are obtained with a 4% concentration, and IOP is reduced significantly (P less than 0.001) between 30 and 240 min after administration of the agent. The decrease in IOP occurs without significant change in tonographic outflow facility. A significant further decrease in IOP can be induced by topical 8BrcGMP in rabbits whose IOP has been lowered by the systemic administration of the carbonic anhydrase inhibitor acetazolamide.