What effect do anticholinergics have in patients with narrow-angle glaucoma?

Anticholinergic medications work by blocking the action of acetylcholine on muscarinic receptors, which has several physiological effects. In the context of narrow-angle glaucoma, the use of anticholinergics can indeed lead to an increase in intraocular pressure.

In narrow-angle glaucoma, the angle between the iris and the cornea is already compromised, leading to difficulties in the outflow of aqueous humor. Anticholinergics cause pupil dilation (mydriasis), which can exacerbate the angle closure, further obstructing the drainage of aqueous humor through the trabecular meshwork. As a result, this increased resistance contributes to elevated intraocular pressure, which can lead to damage to the optic nerve and exacerbate the condition.

The ability of anticholinergics to dilate the pupil is significant in understanding their impact on patients with narrow-angle glaucoma. Therefore, the correct answer relates directly to the adverse effect these medications can have by increasing intraocular pressure in such patients.