22.1 Introduction

Malpositioned or dislocated posterior chamber intraocular lenses (PCIOLs) can lead to significant visual discomfort for patients and surgeons alike. Etiology of this unwanted complication of cataract surgery is best separated into early and late presentation. Early dislocation is typically due to complicated surgery with inadvertent damage to the zonular integrity and capsular support or asymmetric haptic placement. Late dislocations of PCIOLs are frequently caused by progressive zonular dehiscence and capsule fibrosis. Predisposing comorbidities that lead to progressive zonular weakness include eyes with previous surgery, such as trabeculectomy or pars plana vitrectomy, trauma, or pseudoexfoliation.s. Literatur ^,​ s. Literatur ^{,​ 3} Less common conditions associated with zonular weakness include uveitis, retinitis pigmentosa, Marfan’s syndrome, and high axial length. ^{4 ,​ 5} Fortunately, malpositioned or dislocated three-piece PCIOLs can be repositioned and fixated using varied techniques. These techniques include scleral suture fixation (SSF), iris suture fixation (ISF), and, most recently described, intrascleral fixation or glued IOL. ^{6 ,​ 7} A malpositioned three-piece or single-piece PCIOL confined to the capsular bag can readily be repositioned and suture fixated to the sclera via a lasso technique of the haptics, whereas, iris suture fixation is ideal for repositioning a malpositioned or dislocated three-piece PCIOL in the ciliary sulcus. In 1976, Malcom McCannel, MD, first described iris suture fixation to stabilize a three-piece subluxed PCIOL in which the haptics are fixated through a transcorneal approach. ⁸ The Siepser sliding knot for iris repair was later applied and modified for fixation of a three-piece PCIOL. ^{9 ,​ 10} Similarly, iris suture fixation of a foldable three-piece PCIOL can also be applied to secondary IOL placement in the setting of aphakia.s. Literatur ^,​ s. Literatur ^{,​ 13} This allows the surgeon to maintain a small incision and reduce risks associated with large-incision surgery, such as surgically induced astigmatism and potential for suprachoroidal hemorrhage. This chapter discusses the basic technique of iris suture fixation and provides surgical pearls to achieve successful outcomes:

• 
  

  Intracameral pharmacological control of pupil size.

  
  
• 
  

  10–0 polypropylene (CIF-4, Ethicon) or 10–0 polyester (PC-7, Alcon) suture to avoid iris “cheese wiring.”

  
  
• 
  

  Moustache fold technique (3 and 9 o’clock) for secondary IOL iris suture fixation.

  
  
• 
  

  Midperipheral placement and careful titration of suture to avoid ovalized pupil.

22.2 Basic Surgical Technique: Repositioning a Malpositioned Three-Piece PCIOL via Iris Suture Fixation

A variety of factors go into successful iris fixation of a 3-piece IOL (Video 22.1). Surgical technique begins with patient and surgeon comfort. A retrobulbar block is recommended with a 50:50 mixture of longer-acting agents, such as a preservative-free lidocaine 2% and bupivacaine 0.75% to allow for adequate akinesia. Pupil management is key during iris suture fixation. Therefore, it is not recommended to dilate patients preoperatively because it is necessary to bring the pupil down at strategic times during the iris suture fixation technique. Intracameral agents can be used to pharmacologically control the pupil size perioperatively and allow for flexibility of pupil size during surgery. Typically, the retrobulbar block allows for adequate pupillary dilation and visualization of the malpositioned PCIOL. If this is not the case, intracameral agents, such as epi-shugarcaine or preservative-free lidocaine (1%) with phenylephrine (1.5%) can be injected into the anterior chamber to achieve proper dilation. Additionally, mechanical devices, such as iris hooks, may be necessary. As the IOL is lifted into the optic capture position acetylcholine (Miochol, Bausch & Lomb, Inc.) can be injected intracamerally for pupillary constriction during iris suture fixation.

The extent of capsular support should be investigated along with the presence of vitreous in the anterior chamber. If vitreous is present in the anterior chamber, a triamcinolone-assisted anterior vitrectomy with or without a pars plana approach 3.5 mm posterior to the limbus is performed to free the PCIOL from all vitreous adhesions prior to fixation. This reduces vitreous traction and risk of potential retinal comorbidities, such as retinal tears or detachment.

Multiple paracenteses are fashioned using a sideport blade. A dispersive ophthalmic viscosurgical device (OVD) should be instilled into the anterior chamber to protect the endothelium during intraocular manipulation and behind the malpositioned PCIOL to tamponade the posterior capsular bag if present or anterior hyaloid face if the capsule is open. A microsurgical serrated 23-gauge forceps is used to bring the optic on top of the iris in an optic capture position (Fig. 22.1). Miochol is then used to constrict the pupil to allow for stable optic capture and facilitate iris suturing in a midperipheral location. The haptic indentations can typically be visualized behind the iris due to the forced angulation caused by optic capture. If the location of the haptic is not easily identified then one can lift the optic with a spatula or place OVD over the iris to outline the haptic footprint (Fig. 22.2). A 10–0 polypropylene suture (CIF-4 needle, Ethicon) or 10–0 polyester suture (PC-7 needle, Alcon) is then placed through the cornea (via a paracentesis for the Siepser technique), through the iris, under the haptic, back through the other side of the iris, and out of the cornea at the limbus. A 27-gauge cannula can also be used through a paracentesis to retrieve the exiting suture needle for controlled exit out of the eye. The suture size of 10–0 polypropylene versus a 9–0 polypropylene is ideal because of a decreased likelihood of cheese wiring through the iris. In this case, a Siepser tying technique was used to fixate the haptics to the iris. A McCannel or McAhmed suture technique can also be applied to fixate the haptics, depending on surgeon preference (Video 22.2, Video 22.3). The PCIOL is then reposited behind the iris with careful attention not to rotate the haptics out of their respective iris fixation sites. A Sinskey hook or microsurgical forceps can then be used to gently pull the iris into a round configuration. A cat-eye or ovalized pupil appearance after ISF is typically due to sutures that are not midperipheral or tied too tightly. If the pupil has a cat-eyed appearance one can simply throw another suture and cut the suture that is too tight (Video 22.4). The vitrectomy cutter is then used in the I/A cut position to remove all remaining viscoelastic in the event that there are residual vitreous attachments in the anterior chamber.