Optical Biometric Parameters Associated With Intraoperative Floppy Iris Syndrome: A Retrospective Analysis.

To compare ocular biometric measurements between the general population and individuals who developed intraoperative floppy iris syndrome (IFIS) during cataract surgery.

The study took place in a specialized tertiary medical center, focusing on patients undergoing phacoemulsification cataract surgery. Data was collected using IOLMaster700 in a pre-operative setting, allowing for a detailed comparison between those who developed IFIS and those who did not.

Retrospective cohort analysis of patients who underwent phacoemulsification cataract surgery in one tertiary medical center. Biometric data was collected using the IOLMaster700 © in a pre-operative evaluation. Participants who underwent cataract surgery were categorized into two groups: individuals who developed IFIS and individuals who did not develop IFIS. The biometric parameters were then analyzed and compared between the two groups.

A total of 7,386 cataract surgeries were evaluated. Approximately 3% (n=226) of eyes experienced IFIS. Pupil diameter was significantly smaller in patients with IFIS compared to those without IFIS in our study cohort (p < 0.001). In addition, lens thickness was notably larger (p < 0.001), anterior chamber depth (ACD) and aqueous depth p were shallower (p < 0.01) in the IFIS group. Patients with IFIS in the first eye demonstrated an increased risk for IFIS in the fellow eye (p<0.01). Following subgroup analysis, we that patients with pupil diameter < 2.4 mm, ACD < 2.9 mm, and lens thickness> 4.6 mm had a 21% incidence of IFIS.

Our study provides insights into anatomic risk factors associated with IFIS. Correlations identified between biometric measurements and IFIS risk contribute to a comprehensive risk stratification. These findings may guide surgeons in risk assessment and proactive measures before cataract surgeries, especially in individuals with a history of IFIS.