Effect of Prosfaglandin F2a on Aqueous Humor Dynamics of Rabbit, Cat, and Monkey

Topical administration of prostaglandin F2a (PGF2a) produced a reduction in intraocular pressure in eyes of rabbits, cats, and cynomolgus monkeys. In rabbit eyes at 5 or 6 hr, 50 ng, 100 ng, or 250 ng of PGF2a caused a significant intraocular pressure reduction with a small miotic effect. Treatment with 500 ng, 750 fig, or 1000 ng of PGF2a lowered intraocular pressure significantly in cat eyes for at least 24 hr with the development of profound pupillary constriction. Administration of 500 ng, 750 ng, or 1000 ng of PGF2a produced a significant reduction of intraocular pressure in monkey eyes lasting at least 24 hr, with an initial hypertensive phase and a small decrease in pupillary diameter in the treated eyes. Tonography revealed an increased facility of outflow simultaneous with the reduction of intraocular pressure in the eyes of cats and monkeys. These increases of outflow facility could not explain completely the reductions in intraocular pressure. The aqueous humor flow measured by fluorophotometry was unaltered in both species, and possible reasons for this finding are discussed. Anterior chamber aqueous humor protein was significantly higher in cat eyes topically treated with 750 ng of PGF2o than in the diluent-treated fellow eyes. Invest Ophthalmol Vis Sci 25:1087-1093, 1984