Does prior instillation of a topical anaesthetic alter the pupillary mydriasis produced by tropicamide (0.5%)?
Author(s): Haddad DE, Rosenfield M, Portello JK, Krumholz DM Affiliation(s): SUNY College of Optometry, New York, NY 10036, USA. Publication date & source: 2007-05, Ophthalmic Physiol Opt., 27(3):311-4. Publication type: PURPOSE: It is common clinical practice to instill a topical anaesthetic prior to the instillation of a mydriatic agent into the eye. The main rationale for using the anaesthetic is to increase corneal permeability, so that more of the mydriatic agent reaches the receptor sites within the anterior chamber. It addition, as mydriatics generally cause stinging, prior use of an anaesthetic should reduce the degree of discomfort. The aim of the present study was to determine whether the efficacy of mydriasis produced by an antimuscarinic agent is enhanced by prior instillation of a topical anaesthetic. METHOD: The study was performed using a double-masked protocol on 20 healthy young subjects. One drop of either proparacaine (proxymetacaine) (0.5%) or isotonic saline was in
