Which medication class does not primarily lower IOP through increasing aqueous outflow?

Beta blockers lower intraocular pressure (IOP) primarily by reducing aqueous humor production rather than increasing its outflow. This mechanism involves the blockade of beta-adrenergic receptors in the ciliary body, which leads to a decrease in the secretion of aqueous humor.

In contrast, other classes of medications listed have different mechanisms. Prostaglandins primarily work by increasing uveoscleral outflow, thereby enhancing the drainage of aqueous humor and resulting in decreased IOP. Alpha agonists can both reduce aqueous humor production and increase outflow through the uveoscleral pathway. Carbonic anhydrase inhibitors (CAIs) lower IOP mainly by decreasing bicarbonate and aqueous humor production, leading to reduced fluid formation.

Understanding these differing mechanisms is crucial for effectively managing glaucoma and selecting appropriate therapies to lower IOP in patients.