Intraoperative floppy iris syndrome is associated with which class of medications?

• A. Alpha-1 blockers (terazosin, prazosin, Flomax, etc.)
• B. Beta blockers
• C. Calcium channel blockers
• D. ACE inhibitors

Answer: (A)

Intraoperative floppy iris syndrome happens because long-term alpha-1 adrenergic blockade, used for conditions like benign prostatic hyperplasia, diminishes the tone of the iris dilator muscle. When cataract surgery tries to dilate the pupil, the iris becomes flaccid and can billow, prolapse toward the incision, or constrict unpredictably, making the procedure more challenging. This effect is most strongly linked to alpha-1 blockers, particularly tamsulosin, though other drugs in the same class can contribute. The other drug classes listed—beta blockers, calcium channel blockers, and ACE inhibitors—don’t disrupt the iris dilator muscle in this way, so they aren’t associated with IFIS.