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  • Managing Intraoperative Floppy Iris Syndrome

    Cataract/Anterior Segment
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    In 2005, John Campbell and I first described a new small pupil syndrome that we named intraoperative floppy iris syndrome (IFIS) (J Cataract Refract Surg. 2005;31:664-673). Classic IFIS manifests as a triad of intraoperative signs beyond poor pupil dilation: iris billowing and floppiness; iris prolapse to the main and side incisions; and progressive miosis (Figure 1). Particularly if such iris behavior is unexpected, the rate of complications such as posterior capsule rupture, vitreous loss, and iris trauma is increased. We first reported IFIS as being highly associated with the use of tamsulosin (Flomax), a systemic alpha-1 antagonist and the most widely prescribed treatment worldwide for benign prostatic hyperplasia (BPH). Since then, it has become clear that other systemic alpha-1 blockers such as doxazosin (Cardura), terazosin (Hytrin), and alfuzosin (Uroxatral) can also cause IFIS. Nevertheless, the frequency and severity of IFIS is much less with these nonspecific alpha-1 antagonists than with tamsulosin. This difference probably relates to the much stronger affinity and specificity of tamsulosin for the alpha-1A receptor subtype that predominates in both the prostate and the iris dilator muscle.2,3

    Image courtesy David Chang, MD
    Figure 1. Classic IFIS.

     IFIS can be classified as mild (i.e., good dilation; some iris billowing without prolapse or constriction), moderate (i.e., iris billowing with some constriction of a moderately dilated pupil), or severe (i.e., classic triad and poor preoperative dilation). In one prospective study of 167 eyes in patients taking tamsulosin, the distribution of IFIS severity using this scale was as follows: no IFIS (10%), mild (17%), moderate (30%), and severe (43%) (Ophthalmology. In press). Because there is significant variability in IFIS severity among various patients and even between two eyes of the same patient, it is difficult to conclude whether one management strategy is superior to another. In fact, because the various IFIS techniques discussed in this article can be combined, physicians would do well to master several complimentary approaches.

    Pharmacologic Strategies

    A variety of pharmacologic methods for managing IFIS have been proposed.2,4-7 Surprisingly, stopping tamsulosin preoperatively is unpredictable and of questionable value. There are many reported cases of IFIS occurring up to several years after tamsulosin had been stopped. As first described by Sam Masket, preoperative atropine drops (e.g., 1% t.i.d. for 1-2 days preoperatively) can provide sufficient cycloplegia to prevent intraoperative miosis (J Cataract Refract Surg. 2006;32:1603-1605). However, atropine alone is often ineffective for more severe cases of IFIS, so this approach is limited as a single strategy. Because of the potential for acute urinary retention, patients should not stop taking tamsulosin without first consulting their urologist. This is particularly true if preoperative atropine is used.

    Direct intracameral injection of alpha agonists is an excellent pharmacologic strategy for IFIS. The use of phenylephrine to prevent IFIS was first reported by Packard (Eye. 2007;21:331-332) as was epinephrine by Shugar (J Cataract Refract Surg. 2006;32:1074-1075). By presumably saturating the alpha-1A receptors, these agents can further dilate the pupil and restore iris rigidity, thus increasing the iris dilator smooth muscle tone (Figure 2). By increasing iris rigidity, billowing and prolapse are often prevented. Preserved solutions should be avoided, however, and one must use a diluted mixture (e.g., 1:1000 bisulfite-free epinephrine [American Regent] mixed 1:3 with balanced salt solution [BSS] or BSS+) in order to buffer the acidic pH of the commercial preparation.

    Image courtesy David Chang, MD
    Figure 2. Dilation of Pupil.

    Surgical Strategies

    As general surgical principles, physicians should make well-constructed, shelved incisions, perform hydrodissection more gently than usual, and reduce the irrigation and aspiration flow parameters for IFIS patients, if possible. On the other hand, partial thickness sphincterotomies and mechanical pupil stretching should be avoided, because they are ineffective for IFIS and may worsen iris prolapse and miosis.1,2 Bimanual microincisional cataract surgery may be helpful, particularly for mild to moderate IFIS (J Cataract Refract Surg. 2005;31:664-673). This technique utilizes water-tight incisions and allows the surgeon to dissociate the irrigation and aspiration currents. Keeping the irrigation inflow anterior to the iris can lessen iris billowing and prolapse.

    As first described by Bob Osher and Doug Koch, Healon5 (Advanced Medical Optics) is a maximally cohesive ophthalmic visco-surgical device that is particularly well suited for viscomydriasis and for blocking iris prolapse in IFIS (Figure 3).2,8 However, to avoid immediately aspirating Healon5, the surgeon must employ low flow and vacuum rates (e.g., <175-200 mmHg; <26 ml/min). This strategy is, therefore, less suitable if high vacuum settings are desired for denser nuclei. Wendell Scott has proposed injecting Healon5 peripherally over the iris and then filling the central chamber with a dispersive agent such as Viscoat (Alcon Labs) to create a Healon5 “donut.” Viscoat better resists aspiration and this in turn will delay the evacuation of Healon5.

    Image courtesy David Chang, MD.
    Figure 3. Healon5 and IFIS.

    Mechanical Expansion Devices

    A final set of treatment strategies involves mechanical devices to expand and maintain the pupil diameter during surgery. Both the Morcher 5S Pupil Ring and the Milvella Perfect Pupil are disposable, polymethyl methacrylate (PMMA) pupil expansion rings whose grooved contours are threaded alongside the pupillary margin using metal injectors (Figure 4). In contrast, a disposable plastic injector is used to insert Eagle Vision’s Graether disposable silicone pupil expansion ring. All of these rings are more difficult to position if the pupil is less than 4 mm wide or if the anterior chamber is shallow.

    Image courtesy David Chang, MD.
    Figure 4. Morcher Pupil Expansion Ring.

    Iris retractors are the other mechanical strategy for pupil expansion in IFIS. Placement of the hooks in a diamond configuration (Figure 5) has several significant advantages (J Cataract Refract Surg. 2002;28:596-598). The subincisional hook retracts the iris downward and out of the path of the phaco tip. This maximizes exposure in front of the phaco tip, while the nasal hook facilitates chopper placement. One-millimeter limbal paracenteses are made in each quadrant including a separate stab incision made just posterior to the temporal clear corneal incision. In this way, the subincisional hook and the phaco probe occupy separate entry tracks. If the pupil is fibrotic, overstretching it with iris retractors can cause bleeding, sphincter tears, and permanent mydriasis. This typically does not occur with the IFIS pupil, though, because it is so elastic that it readily springs back to physiologic size despite being maximally stretched. Options include 6-0 nylon disposable retractors or reusable 4-0 polypropylene retractors. The latter are the same size and rigidity as an intraocular lens (IOL) haptic, so they are more easily manipulated and can be repeatedly autoclaved, making them more cost effective to use.

    Image courtesy David Chang, MD.
    Figure 5. Reusable Iris Retractors.

    It is much easier and safer to insert iris retractors and pupil expansion rings prior to creation of the capsulorrhexis. If the pupil dilates very poorly or billows during injection of intracameral lidocaine, one should suspect severe IFIS and consider using these mechanical devices. The IFIS pupil often dilates reasonably well preoperatively, however, and it is not until after hydrodissection or during phacoemulsification that prolapse and miosis occur. Healon5 and intracameral epinephrine are excellent "rescue" techniques in this situation where it is difficult to visualize the capsulorrhexis edge as hooks are being inserted. If one chooses to insert iris retractors at this point, one should retract the pupil margin with a second instrument to avoid hooking the capsulorrhexis margin with the retractors.

    Final Recommendations

    Eliciting a history of current or prior alpha-blocker use should alert surgeons to anticipate IFIS and to employ these alternate strategies discussed above either alone or in combination. A prospective multicenter trial using these techniques on 167 consecutive eyes in patients taking tamsulosin demonstrated excellent outcomes and only a 0.6% posterior capsular rupture rate( Ophthalmology. In press). Because of the variability in IFIS severity associated with tamsulosin and other alpha-1 blockers, surgeons may consider using a staged approach in dealing with this condition (J Cataract Refract Surg. 2006;32:1611-1614). Pharmacologic measures alone are often adequate for managing the pupil in mild to moderate IFIS cases. Even if they fail to expand the pupil, intracameral alpha agonists can reduce or prevent iris billowing and prolapse by increasing iris dilator muscle tone. If pupil diameter is still inadequate, viscomydriasis with Healon5 can further expand it for capsulorrhexis. Finally, mechanical expansion devices ensure the most reliable and optimal surgical exposure for severe IFIS and should be considered when other complicating risk factors (e.g., dense nuclei, narrow angles, posterior synechiae, weak zonules, and pseudoexfoliation) are present.

    References
    1. Chang DF, Campbell JR. Intraoperative floppy iris syndrome associated with tamsulosin. J Cataract Refract Surg. 2005;31:664-673.
    2. Chang DF. Chapter 10: Intraoperative floppy iris syndrome.  In: Agarwal A, ed. Phaco nightmares: conquering cataract catastrophies. Thorofare, New Jersey: Slack Incorporated; 2006.
    3. Chang DF, Osher RH, Wang L, Koch DD. A prospective multicenter evaluation of cataract surgery in patients taking tamsulosin (Flomax). Ophthalmology. In press.
    4. Gurbaxani A, Packard R. Intracameral phenylephrine to prevent floppy iris syndrome during cataract surgery in patients on tamsulosin. Eye. 2007;21:331-332.
    5. Shugar, JK. Intracameral Epinephrine for Prophylaxis of IFIS [letter].  J Cataract Refract Surg. 2006;32:1074-1075.
    6. Bendel RE, Phillips MB. Preoperative use of atropine to prevent intraoperative floppy-iris syndrome in patients taking tamsulosin. J Cataract Refract Surg. 2006;32:1603-1605.
    7. Manvikar S, Allen D. Cataract surgery management in patients taking tamsulosin. J Cataract Refract Surg. 2006;32:1611-1614.
    8. Arshinoff SA. Modified SST-USST for tamsulosin-associated intraocular floppy iris syndrome. J Cataract Refract Surg. 2006;32:559-561.
    9. Oetting TA, Omphroy LC. Modified technique using flexible iris retractors in clear corneal cataract surgery. J Cataract Refract Surg. 2002;28:596-598.

    Author Disclosure

    The author discloses that he is a consultant for AMO and Alcon, but has no financial interest in any product or service mentioned, or in any related product or service.