How does Pilocarpine lower intraocular pressure (IOP)?

Pilocarpine lowers intraocular pressure (IOP) primarily by stimulating the longitudinal muscle of the ciliary body, which leads to the opening of the trabecular meshwork (TM). This mechanism enhances aqueous humor outflow from the eye, thereby reducing IOP.

When pilocarpine is administered, it acts as a muscarinic agonist, binding to muscarinic receptors found in the tissues of the eye. The contraction of the longitudinal muscle facilitates the movement of the ciliary body, which in turn pulls on the trabecular meshwork. This action opens the spaces in the trabecular meshwork more widely, allowing aqueous humor to drain more effectively into the Schlemm's canal and subsequently into the venous system.

This outflow pathway is crucial because it addresses the core pathophysiology related to elevated IOP, particularly in conditions such as glaucoma. By improving drainage rather than altering aqueous production or affecting blood flow, pilocarpine is a valuable therapeutic option in managing elevated IOP.

The other choices do not accurately reflect the action of pilocarpine in this context. For example, while increasing aqueous production might be beneficial in certain scenarios, pilocarpine's effects are not oriented toward producing