Purpose: To determine whether topical tranexamic acid can provide acceptable therapeutic concentration in the aqueous humor.
Methods: A total of 47 patients with cataract as the sole eye disease who have been scheduled for cataract operation received one drop of tranexamic acid 5% solution at various time intervals prior to operation (from 15 minutes to 9 hours). Two patients received 10% solution of the drug. Paracentesis of the anterior chamber was done and the aqueous humor was aspirated in the operation room. The aqueous samples were analyzed using high-performance liquid chromatography method with the limit of quantification around 0.1 microg/mL. Systemic and ocular side effects were evaluated.
Results: Aqueous concentrations of tranexamic acid was higher than 1.5 microg/mL up to 160 minutes after administration of a single drop of 5% solution of the drug and then declined to an average concentration of 1 microg/mL at 300 minutes which persisted up to 9 hours after administration.In two patients for whom a single drop of 10% tranexamic acid solution was used, aqueous concentrations of 2.72 and 2.90 microg/mL were detected 60 minutes after administration. None of the patients experienced ocular or systemic side effects.
Conclusions: Topical administration of tranexamic acid is effective in yielding therapeutic intraocular concentrations of drug without any ocular or systemic toxicity.