Intraoperative Floppy Iris Syndrome (IFIS) is more than just a surgical nuisance—it’s a serious complication that can derail cataract procedures and compromise visual outcomes. While α1-blockers like tamsulosin have long been implicated, a groundbreaking pharmacovigilance study has now widened the lens, revealing a broader spectrum of drugs associated with IFIS—and some surprising sex-specific differences.
🔍 What the Study Found
Using over 12 million adverse event reports from the FDA Adverse Event Reporting System (FAERS), researchers applied rigorous disproportionality metrics (ROR, PRR, RRR) and Bonferroni correction to identify statistically significant drug-IFIS associations. The results were eye-opening:
- Top Offenders:
- Imipramine (TCA): ROR = 251.66
- Tamsulosin (α1-blocker): ROR = 171.44
- Chlorpromazine (Antipsychotic): ROR = 91.30
- Female-Specific Signals:
- Brinzolamide (CAI): ROR = 409.63
- Salbutamol (β2-agonist): ROR = 67.12
Beyond these, other implicated classes included corticosteroids, β-blockers, prostaglandin analogs, and 5α-reductase inhibitors like finasteride and dutasteride—even in the absence of α1-blocker use.
đź’Š Key Drug Associations
| Drug/Class | ROR (95% CI) | Notable Findings |
|---|---|---|
| Imipramine (TCA) | 251.66 | Highest IFIS signal |
| Tamsulosin (α1-blocker) | 171.44 | Strong male association |
| Chlorpromazine (Antipsychotic) | 91.30 | Linked to iris dilator atrophy |
| Brinzolamide (CAI) | 409.63 (♀) | Female-specific signal |
| Salbutamol (β2-agonist) | 67.12 (♀) | Female-specific signal |
| Finasteride/Dutasteride | ~50 | Independent of α1-blocker use |
Other implicated drug classes: corticosteroids, β-blockers, prostaglandin analogs, atypical antipsychotics, and carbonic anhydrase inhibitors.
⚠️ Why It Matters
IFIS increases the risk of posterior capsule rupture, vitreous loss, and iris trauma. Alarmingly, only 35% of primary care physicians are aware of the drug–IFIS link, and fewer than 10% routinely ask about cataracts before prescribing α1-blockers.
For female patients, the stakes may be even higher. Though less frequently affected, women experience more severe intraoperative complications—likely due to reduced surgical visibility and underrecognized risk profiles.
🧠Clinical Takeaways
- Always review systemic medications preoperatively, especially in patients with glaucoma, BPH, or psychiatric conditions.
- Consider sex-specific risk stratification—brinzolamide and salbutamol may pose unique risks for women.
- Intracameral epinephrine and NSAIDs offer limited prophylaxis; surgical teams should be prepared for intraoperative maneuvers.
đź“š Citation
Lakhani M, Kwan ATH, Mihalache A, Popovic MM, Hurley B, Muni RH. Drugs Associated With Floppy Iris Syndrome: A Real-World Population-Based Study. Am J Ophthalmol. 2025;275:36–46. doi:10.1016/j.ajo.2025.03.023
