Pilocarpine lowers intraocular pressure in primary open-angle glaucoma primarily by:

• A Reducing aqueous humor production by the ciliary processes
• B Shrinking the ciliary body vasculature through alpha-adrenergic stimulation
• C Increasing uveoscleral outflow through relaxation of the ciliary body
• D Contracting the longitudinal fibers of the ciliary muscle, pulling open the trabecular meshwork and increasing conventional outflow ✓

Explanation

Pilocarpine is a direct muscarinic agonist. Contraction of the longitudinal ciliary muscle fibers pulls the scleral spur posteriorly, opens the intertrabecular spaces of the trabecular meshwork, and enhances conventional outflow facility. This differs from prostaglandin analogues, which increase uveoscleral outflow, and from beta-blockers and alpha-2 agonists, which reduce aqueous secretion. Pilocarpine does not act through adrenergic pathways.

Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.