NBEO Ocular Pharmacology Practice Exam 2025 – Complete Study Guide

The class of medication that is not associated with causing a myopic shift is antihistamines.

Antihistamines are primarily used to treat allergic reactions and conditions such as allergic rhinitis and urticaria. They function by blocking the action of histamine at the H1 receptor, thereby alleviating symptoms such as itching, swelling, and vasodilation associated with allergic responses. While antihistamines can lead to side effects such as dry eyes or blurred vision due to their anticholinergic properties, they do not typically induce a change in refractive error such as a myopic shift.

In contrast, carbonic anhydrase inhibitors, isotretinoin, and diuretics are known to have associations with changes in refractive error. Carbonic anhydrase inhibitors can lead to metabolic acidosis, which may result in a transient myopic shift. Isotretinoin, used for acne treatment, has been associated with changes in ocular parameters, potentially leading to a myopic shift due to corneal flattening or changes in tear film. Diuretics can cause a shift through alterations in fluid balance that may affect the eye’s refractive properties.

Thus, when considering which medication class does not typically lead to a