PURPOSE To evaluate the effect of 8-bromo cGMP (Br cGMP) on aqueous humor flow rate and outflow facility in monkey eyes. METHODS. Aqueous humor flow rate was measured fluorophotometrically after topical, intracameral, or intravitreal administration of Br cGMP in one eye and normal saline in the other eye. Outflow facility was determined by two-level constant pressure perfusion after intracameral bolus injection of Br cGMP in one eye and Bárány’s solution in the other eye.
RESULTS Aqueous humor flow rate decreased by 15% to 20% after intravitreal administration of 10 or 30 micrograms of Br cGMP. There was no flow response to smaller or larger intravitreal doses nor to drugs administered via other routes. Outflow facility increased by 25% to 30% after intracameral infusion of 100 or 300 g Br cGMP, but not after smaller doses.
CONCLUSIONS cGMP may be involved in the regulation of aqueous humor formation and outflow facility and their responses to pharmacologic agents.