Which agent enhances the outflow of aqueous humor and is used to manage glaucoma?

Pilocarpine is a medication that works primarily as a miotic agent, which means it causes the pupil to constrict. This constriction facilitates the opening of the trabecular meshwork, the drainage system for aqueous humor in the eye. By enhancing the outflow of aqueous humor, pilocarpine reduces intraocular pressure, which is essential in the management of glaucoma. The regulation of intraocular pressure is crucial since increased pressure can lead to damage to the optic nerve and vision loss, characteristics of glaucoma.

In contrast, atropine, which is another anticholinergic agent, dilates the pupil and can actually increase intraocular pressure, making it unsuitable for glaucoma management. Ranitidine is an H2 receptor antagonist used primarily for reducing gastric acid secretion and has no role in managing glaucoma. Dexamethasone, a corticosteroid, is used for its anti-inflammatory properties and is not directly involved in the regulation of aqueous humor flow. Therefore, pilocarpine is the correct choice for its specific action in enhancing aqueous humor outflow and effectively managing glaucoma.