Which drug class is associated with iris pigmentation changes, eyelash growth, and conjunctival hyperemia?

• A. Beta blockers
• B. Prostaglandin analogs
• C. Alpha agonists
• D. Carbonic anhydrase inhibitors

Answer: (B)

Prostaglandin analogs are associated with these specific eye changes. They work by activating FP receptors to increase outflow of aqueous humor, which lowers intraocular pressure. The iris pigmentation change happens because prostaglandin signaling can stimulate melanin production in the iris stroma, leading to a darker or more textured iris over time, an effect that is usually permanent. Eyelash growth occurs because prostaglandins influence hair follicles, prolonging the growth (anagen) phase and increasing lash length, thickness, and density. Conjunctival hyperemia arises from prostaglandin-induced vasodilation and increased blood flow to the conjunctiva. These side effects are characteristic of this drug class and help distinguish it from other glaucoma medications, which tend to have different ocular surface or systemic profiles.