Which receptor do topical beta-blockers primarily act upon to reduce intraocular pressure?

Topical beta-blockers primarily act on beta-2 receptors to reduce intraocular pressure. These medications work by decreasing the production of aqueous humor in the eye, which is the fluid that fills the front part of the eye. By binding to the beta-2 adrenergic receptors on the ciliary epithelium, these drugs effectively inhibit the secretion of this fluid, leading to a reduction in intraocular pressure.

It's important to note that while beta-1 receptors are primarily involved in cardiac effects, and alpha-1 receptors are associated with vasoconstriction, the specific action of topical beta-blockers in the eye is focused on the beta-2 receptors. Acetylcholine receptors play no role in this particular pharmacological action. The targeted mechanism of action allows for effective management of conditions such as glaucoma, where controlling intraocular pressure is crucial for preserving vision.