Intraocular pressure is governed by the balance between production and outflow of aqueous humor, so every antiglaucoma pharmacologic class acts by one of exactly two levers: suppressing aqueous humor formation or facilitating its drainage. Ophthalmic pharmacology therefore classifies these agents — topical beta-adrenergic antagonists, carbonic anhydrase inhibitors, direct-acting cholinergic agonists, prostaglandin analogues, and alpha-adrenergic sympathomimetics — by which side of that balance equation they modify, with the therapeutic target being restoration of pressure to the normal physiologic range. Because topically applied drugs can drain through the nasolacrimal system into systemic circulation, the class-specific systemic adverse effects of each agent remain theoretically predictable from its receptor pharmacology, which is why the local route does not exempt an agent from its systemic profile.
Intraocular pressure is governed by the balance between production and outflow of aqueous humor, so every antiglaucoma pharmacologic class acts by one of exactly two levers: suppressing aqueous humor…