**Core Concept:** Beta-blockers are a class of medications used in the treatment of various cardiovascular disorders, including hypertension, angina, and arrhythmias. They exert their effects via binding to beta-adrenergic receptors, which are part of the sympathetic nervous system that controls heart rate and blood pressure. In glaucoma, beta-blockers can also be used to lower intraocular pressure (IOP) by reducing the production of aqueous humor and increasing its outflow through the trabecular meshwork.

**Why the Correct Answer is Right:** Beta-blockers work by blocking the action of catecholamines on beta-adrenergic receptors in the eye. In the context of glaucoma, beta-blockers are selective for beta1 and beta2 receptors, which prevents the stimulation of the sympathetic system. This in turn reduces the release of aqueous humor, a clear fluid produced by the ciliary body, and increases the outflow of aqueous humor through the trabecular meshwork, lowering intraocular pressure and potentially reducing the risk of glaucoma progression.

**Why Each Wrong Option is Incorrect:**

A. This option is incorrect as beta-blockers are selective for beta1 and beta2 receptors, which means they do not target the alpha-adrenergic receptors responsible for increasing IOP in glaucoma.

B. This option is incorrect because beta-blockers are selective for beta1 and beta2 receptors, and do not directly affect the production of aqueous humor or outflow facility.

C. This option is incorrect as beta-blockers are selective for beta1 and beta2 receptors, and do not directly increase aqueous humor outflow through the trabecular meshwork.

D. This option is incorrect because beta-blockers selectively target beta1 and beta2 receptors, not the alpha-adrenergic receptors responsible for raising intraocular pressure in glaucoma.

**Clinical Pearl:** Selective beta-blockers are a valuable option in the management of open-angle glaucoma as they can help reduce intraocular pressure by blocking beta-adrenergic receptors and preventing the increase in aqueous humor production and outflow facility.