EFFECT OF TICRYNAFEN ON AQUEOUS-HUMOR DYNAMICS IN MONKEYS

Objective: To determine the effect of ticrynafen, a nonsulfhydryl-reac tive compound similar to ethacrynic acid, on outflow facility in normo tensive monkey eyes and on intraocular pressure (IOP) in monkey eyes w ith laser-induced glaucoma. Methods: In normotensive eyes, facility (p erfusion) was measured shortly before and after bolus or exchange intr acameral infusion of ticrynafen or vehicle in opposite eyes, and 3.5 t o 4.5 hours after 5 days of twice-daily 2% ticrynafen or vehicle ointm ent. In glaucomatous eyes, baseline and vehicle diurnal IOP curves wer e established, 2% ticrynafen ointment was given twice daily for 5 days , and IOP was measured immediately before and 0.5 to 6 hours after eac h morning treatment. Results: In normotensive eyes, exchange 2-mL. inf usion of 0.2-, 1-, or 4-mmol/L ticrynafen increased facility by 33% +/ - 6% (mean +/- SEM), 73% +/- 18%, and 60% +/- 11%, respectively. Day 5 posttreatment facility was higher in the ticrynafen group than in con trols by 28% +/- 9%. In glaucomatous eyes, maximum IOP decline, from a pproximately 35 mm Hg, was 7.5 +/- 2.0 mm Hg on day 4 and 9.8 +/- 2.4 mm Hg on day 5 of twice-daily ticrynafen treatment. Conclusion: The fa cility-increasing, IOP-lowering action of ticrynafen, ethacrynic acid, and derivatives may not depend entirely on sulfhydryl reactivity. Cli nical Relevance: Whether such drugs as ethacrynic acid and ticrynafen prove valuable for glaucoma therapy, at the least they are useful prob es to study aqueous outflow mechanisms.