Abstract
Abstract: :
Purpose: To evaluate the effect of brimonidine tartrate ophthalmic solution 0.2% on pupil in Chinese normal eyes under dark reflex condition. Methods: Pupil reactions (the pupil area, the amplitude, the latency and the velocity) were measured in 30 eyes of 30 normal Chinese adults under dark–reflex condition using infared pupillarymetry before and after brimonidine tartrate drops were administered. The papillary reactions were subsequently measured after 30 minutes and 4 and 6 hours. Results: 100% of the pupils showed significant moiosis at 30 minutes(P<0.05) . The effect continued in all eyes for 4 hours. At 6 hours, a miotic effect was still present in 78.1%. Under dark–reflex condition, the mydriatic amplitude and speed were reduced (P<0.05) and the mydriatic latency was prolonged(P<0.05) after brimonidine tartrate drops were administered. Conclusions: Brimonidine tartrate could produce significant miosis on the pupil of normal eyes. Reduced speed and smaller amplitude of mydriasis means that the sympathetic function of the pupil was weakened , most likely from the effect of α–2 agonist. The miotic effect may help postoperative patients who report night–vision difficulties related to a large pupil.
Keywords: pupillary reflex • drug toxicity/drug effects • refractive surgery