Review and Update of Intraoperative Floppy Iris Syndrome

Ahmed Sallam; Hany El-Defrawy; Adam Ross; Samer J Bashir; Hamish MA Towler


Expert Rev Ophthalmol. 2011;6(4):469-476. 

In This Article

Intraoperative Floppy Iris Syndrome

Intraoperative floppy iris syndrome (IFIS) represents a spectrum of iris response during phacoemulsification surgery, ranging from iris billowing, to a tendency for the iris tissue to catch the phacoemulsification or irrigation aspiration tip or prolapse toward the main and side-ports incisions, along with progressive intraoperative pupil constriction (Figure 1). IFIS is also associated with inadequate preoperative dilatation of the pupil despite the use of standard dilating drops.[9] In contrast to other causes of small pupil, such as glaucoma and diabetes mellitus, the iris is very elastic and the pupil does not dilate with mechanical stretching, which can even make IFIS worse.[9] IFIS manifests as a continuum of severity with variability between patients and even between eyes of the same patient.[9] The severity can be classified into the following groups:[9]

Figure 1.

Iris billowing, prolapse to corneal incisions and pupil constriction in intraoperative floppy iris syndrome.
Image © Sallam, El-Defrawy, Ross, Bashir & Towler.

  • Mild form, with a well-dilated pupil preoperatively and some intraoperative iris billowing;

  • Moderate form with mid dilated pupil preoperatively and mild tendency of the iris to prolapse through ocular incisions;

  • Severe form where patients have small pupils that resist dilatation and marked intraoperative iris prolapse.

As optimum visualization is crucial for safe removal of cataract, inadequate pupil dilatation will preclude the surgeon's view and compromise the final outcome. Small pupil size prolongs surgery time and increases the risk of posterior capsule rupture and vitreous loss. This, in turn, can increase the risk of postoperative retinal detachment and cystoid macular edema and may limit visual recovery.[10] In addition, the propensity of a floppy iris to prolapse towards the phacoemulsification tip and to the ocular incisions increases the risk of iris injury during the surgery. This may also lead to an exaggerated postoperative uveitis and pupil distortion. In one of the two first independent publications reporting the connection between IFIS and tamsulosin,[9,11] Chang and Campbell retrospectively reported posterior capsular ruptures and vitreous loss in 12% of their tamsulosin patients.[9] Compared with standard figures of posterior capsule ruptures and vitreous loss, this rate is more than ten-times higher than that of a senior grade surgeon,[12,13] and reflects the magnitude of possible IFIS-associated complications when the surgeon is faced with the unanticipated cascade of IFIS.[9]