Effects of topical mydriatics and vasoconstrictors on prostaglandin-E2-induced aqueous flare elevation in pigmented rabbits

We evaluated the effects of topical instillation of mydriatics and vasoconstrictors on prostaglandin E2 (PGE2) induced aqueous flare elevation in pigmented rabbits. Transcorneal diffusion of PGE2 (25 microg/ml) by means of a glass cylinder produced aqueous flare elevation. Mydriatics (atropine sulfate, tropicamide, tropicamide plus phenylephrine hydrochloride, phenylephrine hydrochloride, and cyclopentolate hydrochloride) or vasoconstrictors (naphazoline nitrate and tramazoline hydrochloride) were topically administered before PGE2 application. Aqueous flare was measured with a laser flare-cell meter. One or two instillations of atropine sulfate 1.0%, tropicamide 0.4%, tropicamide 0.5% plus phenylephrine hydrochloride 0.5%, phenylephrine hydrochloride 5.0%, cyclopentrate hydrochloride 1.0%, and naphazoline nitrate 0.05% did not inhibit PGE2-induced aqueous flare elevation. Tramazoline hydrochloride 0.118% inhibited significantly (p < 0.05) PGE2-induced aqueous flare elevation. It is possible that vasoconstriction may be involved partly in inhibition of PGE2-induced aqueous flare elevation by some drugs in pigmented rabbits.