19.1 Introduction

In the setting of absent capsular or zonular support, IOL fixation to the iris can be an attractive alternative for the anterior segment surgeon. This technique can be used for aphakia or to repair a dislocated IOL. McCannel was the first to describe suture fixation of an IOL to the iris in 1976. ¹ The McCannel suture technique requires corneal paracenteses overlying the knots to externalize the sutures. Stark and coauthors described iris fixation of posteriorly dislocated IOLs using the McCannel suture technique in 1980. ² Siepser published his innovative slip knot technique in 1994. ³ This suture technique allowed knot tying within a closed anterior chamber and did not require additional paracenteses. Condon ⁴ and later Chang ⁵ employed the Siepser technique when fixating IOLs to the iris. These techniques all use a single suture needle pass to fixate the haptics of an IOL to the iris. Although these techniques are extremely useful for IOL fixation, often the iris and pupil are left distorted (▶Fig. 19.1).

In contrast, double-needle iris/IOL fixation uses a suture needle, like a third hand within the anterior chamber, to lift and stretch the peripheral iris prior to suture fixation. This technique allows the surgeon to support the IOL with suture bites, which are smaller and more peripherally positioned in the iris, thereby minimizing iris and pupillary distortion. Suture fixation of a dislocated IOL is primarily reserved for IOLs, which are not within the capsular bag and are of a three-piece design. Iris fixation of single-piece polymethyl methacrylate IOLs is possible but technically more difficult, especially if the IOL is planar in design.

19.2 Description of the Technique

Prior to fixation of a dislocated IOL to the iris, the surgeon must assess the status of the vitreous in relation to the IOL. Appropriate limbal or pars plana vitrectomy should be performed if there is vitreous in the anterior segment or adherent to a dislocated IOL to avoid creating vitreous traction on the retina.

Assessment of the IOL position within the eye is a critical first step in managing IOL dislocation. If the IOL is in the anterior vitreous, a pars plana posterior-assisted levitation ⁶ may be necessary to bring the IOL into the anterior chamber. It is also critical to determine whether the IOL is right side up (▶Fig. 19.2). If the IOL is inverted, it should be flipped so that it is right side up prior to fixation. This maneuver should be performed after appropriate vitrectomy.

For dislocated IOLs located in the capsular bag or ciliary sulcus, an anterior approach through two paracenteses is sufficient to deliver the optic anterior to the pupil. The 1-mm paracenteses are created at the superior temporal and inferior temporal limbus. A miotic agent (Miochol) is injected into the anterior chamber. After miosis of the pupil, a dispersive ophthalmic viscosurgical device (OVD) is instilled into the anterior chamber. The optic of the IOL is visualized by retracting the iris with a Kuglen hook. A 27-G OVD cannula is passed through the pupil and then beneath the optic of the IOL. The optic is elevated through the pupil with the 27-G cannula. The iris is pushed off the opposite side of the optic with a Kuglen hook. This maneuver captures the optic anterior to the iris while the haptics remain posterior. Equal amounts of iris should be distributed between the two haptics. An oblique paracentesis is created approximately 90° away from where the haptic is located beneath the iris. The proper placement of this paracentesis is best visualized by drawing an imaginary line parallel to the haptic (▶Fig. 19.3). The internal opening of the paracentesis should touch this line. A 10–0 Prolene suture double armed with CTC-6L needles (Ethicon) is used for this technique. One needle is cut free. This free needle is passed through the oblique paracentesis then through and through the iris capturing the underlying haptic (▶Fig. 19.4). The needle tip is swept away from the iris root and then driven into the peripheral cornea (▶Fig. 19.5). This maneuver achieves four important objectives: it decreases the angle between the iris and the cornea, stretches the iris away from the iris root, fixates the stretched iris to the cornea, and drapes the iris over the haptic highlighting the area for suture fixation. The CTC-6L needle with attached 10–0 Prolene suture (Ethicon) is then passed through the oblique paracentesis, posterior to the first needle. As the iris has been placed on stretch by the first needle, and more of the peripheral iris is visible, the second needle can be passed more peripherally into the iris for haptic fixation. Keeping the peripheral iris under tension allows the second needle to take a smaller, more controlled bite of iris tissue. The bite of iris tissue should be taken perpendicular to the underlying haptic (▶Fig. 19.6). Both needles are then removed from the eye. The same suturing technique is performed on the second haptic. Both sutures are tied with a double overhand knot using the Siepser sliding knot technique. ³ It is important to not finish or lock the knots at this point. The optic of the IOL is then prolapsed through the pupil. Once the optic is posterior to the pupil, the distorting effects of the sutures on the iris and pupil can be evaluated. As the sutures are not locked, iris tissue can be mobilized through the knots by pulling on the pupil margin with micrograspers if iris or pupillary distortion is present. If this maneuver does not relieve iris distortion, the suture should be removed and double-needle iris/IOL fixation may be repeated for that haptic. The knots are then locked with two single overhand knots utilizing the Siepser sliding knot technique.