Snapshot A 56-year-old man presents to the emergency department with severe eye pain, headache, and blurry vision. His symptoms developed while watching a movie. On physical examination, he has reduced visual acuity and a mid-dilated right pupil that is cloudy and poorly responsive to light. Intraocular pressure is 55 mmHg (normal is 8-20 mmHg). (Acute angle-closure glaucoma) Introduction Glaucoma is an optic neuropathy leading to optic nerve head atrophy typically associated with an elevated intraocular pressure The goal of treatment is to decrease intraocular pressure aqueous humor production begins in the nonpigmented epithelium of the ciliary body α-agonists, β-blockers, and carbonic anhydrase inhibitors act here the aqueous humor then flows from the posterior chamber → anterior chamber → trabecular meshwork → canal of Schlemm the uveoscleral outflow can be influenced by prostaglandin analogs the trabecular outflow can be influenced by cholinomimetics TABLE Glaucoma DrugsMedicationMechanism of ActionSide Effectsα2-agonistsBrimonidine↓ aqueous humor productionAllergic and follicular conjunctivitisContact dermatitisBlurry visionβ-blockersTimolol, betaxolol, and carteolol↓ aqueous humor productionNo changes in pupil size or visionCarbonic anhydrase inhibitorAcetazolamide↓ aqueous humor production via inhibition ofcarbonic anhydraseNo changes in pupil size or visionCholinomimeticsPilocarpine and carbachol↑ aqueous humor outflow viaciliary muscle contraction bydirectly stimulating cholinergic receptorsPhysostigmine and echothiopate↑ aqueous humor outflow viaciliary muscle contraction byindirectly stimulating cholinergic receptorsMiosisCyclospasmProstaglandinsBimatoprost and latanoprost are PGF2α analogs that↑ aqueous humor outflowPeriocular hyperpigmentationIncreased and/or misdirected eyelash growth