Which of the following does not cause mydriasis?
Pilocarpine cause miosis, not mydriasis Sympathomimetic drugs cause contraction of dilator pupillae and thus result in active mydriasis whereas parasympathomimetic drugs contract sphincter pupillae leading to active miosis. Parasympatholytic drugs like atropine stop the action of ACh on sphincter pupillae resulting in passive mydriasis. Effect Mechanism Drug Group Responsible Examples Active mydriasis Contraction of dilator pupillae Sympathomimetic drugs Phenylephrine ,Cocaine, Amphetamines Passive mydriasis Relaxation of sphincter pupillae Anti-cholinergic drugs Atropine ,Homatropine, Tropicamide Cyclopentolate Active miosis Contraction of sphincter pupillae Cholinergic drugs Pilocarpine, Physostigmine Passive miosis Relaxation of dilator pupillae Anti-adrenergic drugs Clonidine
Atropine
Phenylephrine
Tropicamide
Pilocarpine
Parasympathetic System & Glaucoma