Why is tricamide contraindicated in patients with open angle glaucoma?

Tricamide is contraindicated in patients with open-angle glaucoma primarily because it causes pupil dilation. This dilation, a condition known as mydriasis, can lead to increased intraocular pressure in individuals who already have compromised drainage systems in their eyes, such as those with open-angle glaucoma.

In open-angle glaucoma, the normal fluid drainage pathways in the eye are partially obstructed, leading to increased pressure that can damage the optic nerve. When certain medications, like tricamide, induce pupil dilation, the muscles controlling the iris may physically block the trabecular meshwork, which is responsible for draining aqueous humor. This blockage can exacerbate the existing intraocular pressure and potentially worsen the patient's condition, making the use of tricamide risky in these patients.

The other options do not apply to the mechanism of tricamide in this case, as it does not cause excessive inflammation, decrease intraocular pressure, or induce cataract formation in a relevant way that would be a direct concern for patients with open-angle glaucoma.