All of the following drugs causes mydriasis except: March 2012

Ans: B i.e.. Pilocarpine Cholinergic stimulation causes contraction of both the pupil & the ciliary body, while sympathomimetic stimulation leads to dilatation of the pupil Anticholinergic dilates pupil causing mydriasis & impair accommodation leading to cycloplegia Drugs & uses Phenylephrine 5%-10%, a selective alpha-1 agonist, dilates pupil & are used prior to fundus examination or retinal laser procedures Pilocarpine (parasympathomimetic) use in glaucoma is limited by the occurrence of miosis, browache & accommodative spasm Epinephrine 1% (adrenaline) use is contraindicated in patients with narrow anterior chamber angles due to the mydriasis it produces. Commonly used cycloplegics (anticholinerics) are atropine 1%, homatropine 2%, cyclopentolate 1% & tropicamide 0.5%