Cholinergic drugs such as pilocarpine are routinely used to treat glaucoma. What is their mechanism of action in the eye that accounts for this ophthalmologic use?
Like other cholinergics with muscarinic action, pilocarpine improves the drainage of aqueous humor from the anterior chamber angle of the eye. The cholinomimetic effect results in contraction of the ciliary body and causes a change in its position. This altered position increases flow of aqueous humor through the trabecular network and into the canal of Schlemm, thus decreasing the intraocular pressure of glaucoma. Ref: Brown J.H., Laiken N. (2011). Chapter 9. Muscarinic Receptor Agonists and Antagonists. In L.L. Brunton, B.A. Chabner, B.C. Knollmann (Eds), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.
Reduction in the formation of aqueous humor
Blockade of adrenergic receptors to potentiate cholinergic effects
Alkalinization of aqueous humor
Improved drainage of aqueous humor