Which two types of eye drops could potentially trigger an attack of angle-closure glaucoma in patients with narrow anterior chamber angles?

Mydriatics and cycloplegics are types of eye drops that can lead to an attack of angle-closure glaucoma, particularly in individuals with narrow anterior chamber angles.

Mydriatics work by dilating the pupil, which can cause the iris to move forward and narrow the angle between the iris and the cornea. This reduced angle can lead to an obstruction of the aqueous humor drainage, ultimately resulting in increased intraocular pressure and a potential angle-closure glaucoma attack.

Cycloplegics also affect the positioning of the iris by temporarily paralyzing the ciliary muscle, which can further contribute to the forward displacement of the iris. This forward movement exacerbates the narrowing of the angle, increasing the risk for angle-closure glaucoma in susceptible individuals.

In contrast, other classes of medications such as beta blockers and prostaglandins primarily focus on reducing intraocular pressure without causing significant changes in pupil size or iris position. Similarly, carbonic anhydrase inhibitors and alpha agonists also have different mechanisms that do not induce pupil dilation. Antihistamines and steroids might have various side effects, but they are less likely to cause acute angle closure as they do not directly interfere with the relationship between the lens, iris, and cornea