What is the primary effect of pilocarpine in glaucoma management?

• A. It increases ciliary blood flow
• B. It reduces aqueous humor production
• C. It dilates the pupil
• D. It increases trabecular outflow by inducing miosis via muscarinic stimulation

Answer: (D)

Pilocarpine lowers intraocular pressure mainly by increasing the outflow of aqueous humor through the trabecular meshwork. It does this by directly stimulating muscarinic receptors on the ciliary muscle, causing contraction. That muscle contraction opens up the drainage pathways, boosting drainage via the conventional outflow pathway. The drug also causes pupil constriction (miosis), which can help widen the anterior chamber angle and aid drainage, especially in angle-closure scenarios. The key point is that the therapeutic effect comes from enhanced trabecular outflow, not from reducing aqueous production, and it isn’t about dilating the pupil.