Intraoperative floppy iris syndrome (IFIS) during phacoemulsification is most commonly caused by prior use of which systemic drug class, and what is the preferred intraoperative management?

• A Anticoagulants (warfarin); preoperative discontinuation 5 days before surgery
• B ACE inhibitors; increase irrigation bottle height to maintain anterior chamber
• C Alpha-1 antagonists (tamsulosin); intraoperative iris hooks, Malyugin ring, or intracameral phenylephrine-ketorolac ✓
• D 5-alpha reductase inhibitors (finasteride); preoperative atropine drops

Explanation

IFIS is caused by alpha-1A adrenergic receptor blockade from systemic tamsulosin (and other uroselective alpha-1 antagonists used for BPH), preventing iris dilator muscle stimulation. IFIS triad: billowing iris stroma, iris prolapse through incisions, progressive intraoperative miosis. Management strategies include: preoperative intracameral phenylephrine (with or without ketorolac, e.g., OmniGuard/Shugarcaine mix), iris retractors or Malyugin expansion rings, and small volume cohesive OVD to stabilise the anterior chamber. Stopping tamsulosin preoperatively does not reliably reverse IFIS due to permanent receptor down-regulation. Chang and Campbell first described this syndrome in 2005.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.