The study found higher odds of intraoperative floppy iris syndrome, or IFIS, among patients with 10 years or more of opium use who underwent phacoemulsification. In the multivariable analysis, the adjusted odds ratio was 1.79, with a 95% confidence interval of 1.1 to 2.7. In this context, an adjusted odds ratio is the comparison after the model considers the recorded factors together. Because this was a cohort study, the result shows an association and does not establish that opium use caused IFIS.
Alpha-blocker use was associated with higher odds of IFIS in the multivariable analysis. The adjusted odds ratio was 11.3, with a 95% confidence interval of 6.1 to 20.7.
Pseudoexfoliation syndrome, an ocular factor tracked in the study, was also associated with higher odds of IFIS. Its adjusted odds ratio was 1.88, with a 95% confidence interval of 1.1 to 3.02. Increasing age was independently associated with IFIS, with an adjusted odds ratio of 1.01 and a 95% confidence interval of 1.00 to 1.02.
How often IFIS occurred
IFIS occurred in 223 of the 1,722 patients in the cohort, a cumulative incidence of 13.0%. The 95% confidence interval for that estimate was 11.4% to 14.6%, giving the range of uncertainty reported by the researchers.
The prospective cohort included patients aged 40 to 90 undergoing phacoemulsification with posterior-chamber intraocular lens implantation at a tertiary care center from March 2024 through April 2025. The study set out to identify demographic, ocular, comorbidity, medication and opium-use factors associated with IFIS.
What the researchers measured
Patients with a history of ocular surgery, trauma or advanced ocular diseases were excluded. The researchers collected demographic data, ocular parameters, comorbidities, medication use, alpha-blocker use, pseudoexfoliation status and opium-use duration. They graded the severity of IFIS during the operation using the Chang and Campbell criteria.
Researchers used bivariable and multivariable logistic regression to examine which recorded factors were associated with IFIS. The multivariable analysis considered the measured factors together and produced the adjusted odds ratios reported for alpha-blocker use, pseudoexfoliation syndrome, long-term opium use and age.
The authors call for a fuller history
In their conclusion, the authors list increasing age, shorter axial length, an eye-length measurement, smaller pupil size, alpha-blocker use, pseudoexfoliation syndrome and opium use lasting at least 10 years as key predictors of IFIS. They distinguish long-term use from shorter use, reporting increased risk with 10 years or more but not with shorter use.
The authors say that a comprehensive review of medication and opium-use history is essential for mitigating surgical complications.
The result needs caution
The evidence is limited to the described cohort: patients aged 40 to 90 undergoing phacoemulsification with posterior-chamber lens implantation at a tertiary care center. It does not show that opium use, alpha-blocker use, pseudoexfoliation syndrome, age or the ocular measurements caused IFIS. Nor does it show that reviewing these histories reduces IFIS or surgical complications.
The conclusion includes shorter axial length and smaller pupil size among the predictors, but the reported results do not give effect estimates or uncertainty intervals for those two factors. The study also leaves open how IFIS risk varies across more detailed opium-use durations and doses, and whether the reported associations persist in other clinical settings.
Paper data and sources
Original title: Intraoperative floppy iris syndrome in cataract surgery: effects of opium use.
Authors: Hamid Sadeghi, Hamid Sharifi, Naser Nasiri, Ali Sharifi
Journal/Repository: International ophthalmology
Status: Peer-reviewed
First online: 2026-08-21
DOI: 10.1007/s10792-026-04174-9
Original paper · Full text