Which class is commonly used as a second-line option when prostaglandin analogs do not achieve target IOP?

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

Answer: (A)

When prostaglandin analogs don’t bring IOP down to the target, a second medication with a different mechanism is added to push the pressure lower further. Beta blockers fit this role well because they decrease aqueous humor production at the ciliary body, giving an additional, complementary reduction in IOP beyond what the prostaglandin analogs achieve by increasing outflow. This combination is a common and effective strategy: one drug mainly boosts outflow, the other reduces production, leading to a greater overall drop in IOP. Other classes, like carbonic anhydrase inhibitors or alpha agonists, can be used as well, but historically beta blockers have been a standard second-line option when prostaglandin analogs alone don’t reach the goal. Be mindful of systemic or respiratory side effects with beta blockers, which can influence the choice in certain patients.