Intraoperative floppy iris syndrome (IFIS) is a surgical condition characterized by a triad of findings: a flaccid iris billowing through the surgical incision, iris prolapsed and intraoperative papillary constriction. IFIS both complicates the surgical procedure, and increase risk for postoperative complications (retinal detachment & endophthalmitis) related to posterior capsular rupture and lens fragments within the vitreous.
Alpha-1-antagonists used for urinary symptoms or hypertension can cause IFIS.
Terazosin, Doxazosin and Prazosin are examples of such antihypertensive.
Tamsulosin, Alfuzosin are examples of alpha blockers used for urinary symptoms.
Tamsulosin, with particular affinity for the alpha 1a receptor, has particularly been associated with IFIS. Poor pupillary dilation in patients receiving alpha-1-antagonists can be a clue that IFIS physiology has developed.
Patients should be asked about use of alpha-1-antagonists during the preoperative evaluation. Clinical impression is that the drug effect is long-lasting (weeks, months, or years) and most eye surgeons do not insist that these agents be discontinued. Various preoperative and intraoperative regimens can reduce IFIS (e.g. preoperative cycloplegia, low flow fluids, iris retractors and pupillary ring expanders)
Incidence of IFIS among those receiving Tamsulosin is reported to vary between 37.9 and 90%. It should be noted that while IFIS was classically described in males, the increased use of Tamsulosin for various urological indications in females may result in more females developing IFIS in the future.
There are several reports suggesting that IFIS can occur within weeks of commencing Tamsulosin and one case report showed that IFIS can develop as early as 2 days after treatment. Tamsulosin has a long half-life, with detectable levels in the aqueous humor of patients who stopped the medication up to 28 days previously. Nevertheless, discontinuation of Tamsulosin therapy preoperatively for periods longer than 28 days (and sometimes for several years) does not necessarily eliminate the occurrence of IFIS.