This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
[{'content': 'All of the following drugs causes mydriasis except: March 2012 \nSelect and explain. \nA. Phenylephrine, B. Pilocarpine, C. Epinephrine, D. Atropine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 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%', 'role': 'assistant'}]