EPSILON-AMINOCAPROIC ACID DOES NOT INHIBIT OUTFLOW RESISTANCE WASHOUTIN MONKEYS

Purpose. To determine whether the anti-fibrinolytic agent epsilon-amin ocaproic acid (EACA) inhibits the washout of resistance to aqueous hum or outflow during anterior chamber perfusion in cynomolgus monkeys, as it does in rabbits. Methods. Nine adult ocular normotensive cynomolgu s monkeys underwent bilateral anterior chamber perfusion with Barany's solution, containing 3.8 mM EACA unilaterally. Total outflow facility was determined in both eyes simultaneously for approximately 4 hours by the two-level constant pressure method. The data were analyzed usin g a linear regression model that tested treated versus control eye dif ferences over time against a slope and intercept of 0.0. Results. Outf low facility increased and resistance decreased significantly over tim e similarly in both EACA-treated and control eyes; i.e., neither the s lopes nor the intercepts for facility or resistance, respectively, dif fered between the eyes over the entire 4-hour measurement period or fo r the initial 90 minutes considered separately. The facility increase and resistance decrease as functions of perfusion volume also were sim ilar in EACA-treated and control eyes. Conclusions. EACA at this dose does not prevent resistance washout in the cynomolgus monkey, in contr ast to the rabbit. This species difference may relate to the vastly di fferent anatomy and physiology of their outflow pathways.