Additive Effect of Pilocarpine and Timoptol on the Diameter of the Pupil and onVOT in Healthy Rabbits

Overview

In the submitted paper experimental results are interpreted comparing theadministration of two fundamental anti-glaucomatous drugs into the conjunctiv-cal sac of healthy rabbits of the Chinchilla strain. The authors administered 2%pilocarpine and 0.25% Timoptol(Timololi maleas, Léeiva) alone, as combinedconsecutive administration and concurrent administration. The greatest effecton the width of the pupil and on IOP was exerted before 60 minutes by adminis-tration of pilocarpine, then Timoptol resp. And after 60 minutes the mixture ofthe two substances was most effective. This effect is explained by the additiveaction via substances produced by interaction (metabolites). Pilocarpine beinga cholinergic substance promotes formation of the vitreous fluid and thus also anincreased supply of free amino acids into ciliary body processes and the vitreousfluid. Timoptol then interacts with the increased amount of free amino acids andthus a greater and longer reduction of VOT occurs than after the action of newlyformed cholinergic or newly formed adrenergic substances alone.

Key words:
parasymathicomimetics and non-selective beta-blockers, action of 2%pilocarpine and 0.25% timolol on pupil and IOP, additive action of anti-glaucoma-tous drugs in the treatment of glaucoma.