Which type of medication can be used to achieve mydriasis during ocular examinations?

Mydriasis, the dilation of the pupils, is commonly achieved using cycloplegic agents during ocular examinations. These medications work by temporarily paralyzing the ciliary muscle of the eye, which not only dilates the pupil but also prevents the lens from changing shape. This allows for a more comprehensive observation of the internal structures of the eye, such as the retina and optic nerve, without the interference of accommodation—the eye’s ability to focus.

Cycloplegic agents specifically target the muscarinic receptors in the iris and ciliary body, leading to effective dilation necessary for ophthalmic assessments. They are often used in procedures where detailed visualization of the back of the eye is required, such as during a fundus examination.

Other medications mentioned, like anti-inflammatory agents, antihistamines, and antibiotics, are not designed for causing mydriasis. Anti-inflammatory agents are typically used to reduce inflammation and pain in the eye, antihistamines may be used to treat allergic reactions or symptoms but do not induce pupil dilation, and antibiotics are used to treat bacterial infections, not for altering pupil size. Thus, the role of cycloplegic agents is distinct and vital for achieving mydriasis effectively during ocular exams.