Prospective analysis of anatomic features predisposing patients to intraoperative floppy iris syndrome

Purpose To aid preoperative risk assessment by identifying anatomic parameters corresponding with a higher risk of intraoperative floppy iris syndrome (IFIS) during cataract surgery. Methods Prospective cohort study of 55 patients with a1-adrenergic receptor antagonist (a1-ARA) treatment and 55 controls undergoing cataract surgery. Anterior segment optical coherence tomography (AS-OCT), video pupilometer, and biometry measurements were performed preoperatively and analyzed regarding anatomic parameters that corresponded with a higher rate of IFIS. Those statistically significant parameters were evaluated with logistic regression analysis and receiver operating characteristic (ROC) curve. Results Pupil diameter was significantly smaller in patients who developed IFIS compared to those who did not develop IFIS (AS-OCT 3.29 +/- 0.85 vs. 3.63 +/- 0.68, p = 0.03; Pupilometer 3.56 +/- 0,87 vs. 3.95 +/- 0.67, p = 0.02). Biometric evaluation revealed shallower anterior chambers in the IFIS group (ACD 3.12 +/- 0.40 vs. 3.32 +/- 0.42, p = 0.02). Cutoff values for 50% IFIS probability (p = 0.5) were PD = 3.18 mm for pupil diameter and ACD = 2.93 mm for anterior chamber depth. ROC curves of combined parameters were calculated for a1-ARA medication with pupil diameter and anterior chamber depth, which yielded an AUC of 0.75 for all IFIS grades. Conclusion The combination of biometric parameters with history of a1-ARA medication can improve assessment of risk stratification for IFIS incidence during cataract surgery.