Intraoperative Floppy Iris Syndrome (IFIS) Associated with Systemic Alpha-1 Blockers ASCRS and AAO Educational Update Statement

Since intraoperative floppy iris syndrome (IFIS) was first described in 2005, its association with the systemic alpha-1 adrenergic antagonist, tamsulosin (Flomax®, Boehringer-Ingelheim Pharmaceuticals, Inc., Ridgefield, CT), has become well established [1-7]. The clinical manifestations of IFIS complicating cataract surgery are poor preoperative pupil dilation, iris billowing and prolapse, and progressive intraoperative miosis [1]. In one prospective study, 90% of 167 eyes from patients taking tamsulosin exhibited some degree of IFIS during cataract surgery [5]. Until recently, tamsulosin has been the only systemic alpha-1 antagonist which is selective for the alpha-1A receptor subtype [8]. IFIS has also been reported with non-subtype specific alpha-1 adrenergic antagonists, such as terazosin (Hytrin®; Abbott Laboratories, Inc., North Chicago, IL), doxazosin (Cardura®; Pfizer Inc, New York, NY), and alfuzosin (Uroxatral®; Sanofi-Aventis, Paris, France). However, several prospective and retrospective studies suggest that IFIS is more likely to occur with tamsulosin than with the non-specific alpha-blockers [1-3, 6, 9]. Tamsulosin and alfuzosin are considered to be uroselective and less likely to cause postural hypotension [7]. Recently a new alpha-1A subtype specific antagonist, silodosin (Rapaflo), was approved for BPH, and it is anticipated that it will also cause IFIS.