The free amino acids and the aqueous humor pH after antiglaucomatics in vitro

Authors present comparison of the previous results on the influence of free amino acids of the aqueous humor in rabbits and human on the pH of the aqueous humor in vitro. Four clinically used antiglaucomatics were added (2% Trusopt--pH 5.33; 0,005% Xalatan--pH 6.4; 0.5% Timoptol--pH 6.80 and 1% Pilocarpine--pH 5.87) into the aquired aqueous humor of rabbits (pH 7.59) and human (pH 7.11 +/- 0.11). After their instillation pH of the aqueous humor immediately decreased towards acid levels. The pH changes after Timoptol, Xalatan and Pilocarpine showed a similar time pattern and after return to the baseline values the pH shifted to alkaline levels. In case of Trusopt instillation the pH value reached the baseline of the aqueous humor after 240 min. Almost no pH changes were recorded from 240 min up to 24 hours after all tested antiglaucomatics. From the wiev on the speed of activity and effectivity depending on time required to reach the initial pH value of the aqueous humor we to make this order: Pilocarpine>Timoptol>Xalatan>Trusopt. Comparing our results the effect of antiglaucomatics is connected with different composition and also with shift of the aqueous humor pH towards slightly alkaline level (similar effect in rabbits and human). Results presented in this work are theoretical but also practical contribution to the treatment of glaucoma. (Fig. 1, Ref. 38.).