Repositioning a posteriorly dislocated silicone plate haptic toric intraocular lens

Abstract

The incidence of late intraocular lens (IOL) dislocation is increasing, and various techniques have been described to reposition a dislocated IOL. However, no techniques have been described for safely repositioning an in-the-bag dislocated silicon plate haptic toric IOL. This case describes a technique for repositioning an encapsulated, posteriorly dislocated silicone plate haptic toric IOL while preventing further dislocation into the vitreous cavity. Sutures of 10–0 polypropylene were utilized to ensure safe retrieval of the dislocated IOL. An anterior vitrectomy was then performed to remove the contracted capsular bag around the IOL. The IOL fixation hole was temporarily externalized to allow quick and secure IOL fixation, eliminating the risk of losing the slippery silicon IOL into the vitreous cavity. Using our technique, the IOL was successfully placed in the proper position and resulted in good vision for the patient, while avoiding the trauma of lens exchange.

Introduction

Late intraocular lens (IOL) dislocations are increasing. In a study of 123 eyes, Dabrowska-Kloda et al found that the cumulative risk for late in-the-bag lens dislocations after cataract extraction was 0.09% at 5 years, 0.55% at 10 years, 1% at both 15 and 20 years postoperatively. Moreover, it was found that there was an increased likelihood for dislocations for lenses implanted between 2002–2012 as compared to 1992–2001 (0.89% vs. 0.39%, P<0.001, respectively).¹ Thus, it seems that late in-the-bag dislocations are occurring at an increased frequency overall, as well as with recently implanted lenses.

A wide variety of techniques for IOL repositioning are available, with variations depending on individual patient circumstances. Scleral fixation is the most common approach, but other techniques have also been described.^2–6 However, none of the previously reported techniques provide a solution for the correction of a displaced plate haptic toric lens located posterior to the iris. We describe here one successful method for correcting such a dilemma.

Technique

A 70-year-old male was referred to us with decreased vision. He had a dislocated, encapsulated STAAR silicone plate haptic toric IOL (STAAR Surgical Company, Monrovia, CA) in the right eye with the superior temporal pole in the anterior chamber, the inferior-nasal pole in the posterior chamber, and the optic captured in the iris plane (Figure 1). The plate haptic IOL had 2 fixation holes in the long axis, one on each end. It was determined surgical repair was necessary to reposition the lens.

Figure 1.

Whole eye (A) and slit lamp (B) images demonstrating the superior temporal pole of the plate haptic toric lens in the anterior chamber, with the inferior-nasal pole in the posterior chamber.

Prior to surgical repair, while the patient was in the preoperative holding area, the lens was found sitting in the normal capsular plane posterior to the iris but freely mobile. In addition, the whole lens was compressed inside the capsule and under tension. Phimosis was present, preventing the lens from lying flat. In addition, there were few, if any, zonules left. Once in the operating room, a safety suture grid first described by Masket and Fram⁷ was placed to prevent further descent of the IOL into the vitreous. A double-armed CTC6L needle with 10–0 polypropylene safety sutures was passed through the pars plana inferiorly, behind the IOL, and the sutures were retrieved superiorly through the pars plana with a 27-gauge hypodermic needle, dividing the horizontal white-to-white space into thirds. The needles were then cut off, and sutures tied, forming 2 vertical suture lines behind the IOL. This process was repeated to divide the vertical white-to-white space into thirds and create a safety grid (Figure 2).

Figure 2.

Demonstration of dividing the perpendicular white-to-white space into thirds to create a safety grid.

The meridians of the IOL fixation were marked at 170 and 350 degrees, the proper lens alignment for this patient as determined by preoperative topography. Hoffman’s pockets were created at each IOL fixation meridian.⁸ Superior and inferior paracenteses were then created, and viscoelastic injected into the anterior chamber. Iris hooks were used to retract the iris for visualization of the IOL. Sandwiching the IOL between a Koch spatula and a cyclodialysis spatula, the lens was then carefully guided into the anterior chamber.

To relieve the tension surrounding the IOL, an anterior vitrectomy was performed. During the anterior vitrectomy, the phimotic capsular bag material was removed, leaving the IOL free floating. A 3 mm limbal incision was then made inferotemporally. The IOL was oriented in the same meridian as the limbal wound with one fixation hole resting in the anterior chamber just inside the limbal wound. A 0.12 mm forceps was used to grab the fixation hole through the main wound to externalize it. Double-armed 9–0 polypropylene sutures attached to a CTC6L needle were placed through the fixation hole (Figure 3) and tied into a Girth Hitch knot (Figure 4). Releasing the grasp of the 0.12 mm forceps allowed immediate repositioning of the entire plate haptic IOL back into the anterior chamber with the fixation hole attached to the double-armed polypropylene sutures. As the intended fixation site and the wound were within 60 degrees, it was difficult to pass the suture from wound to fixation site. Then both polypropylene sutures were sequentially passed from the wound to the superior nasal paracentesis and retrieved through a 26-gauge cannula (Figure 5).

Figure 3.

Securely tying one of the fixation holes using a double-armed 9–0 polypropylene suture as the haptic is temporarily pulled outside the limbal wound.

Figure 4.

Girth Hitch knot.

Figure 5.

Passage of a CTC6L needle with attached polypropylene suture via the 26-gauge cannula.

By gently pulling both polypropylene sutures, the plate haptic IOL was easily rotated 180 degrees, and the other fixation hole was then resting just inside the inferotemporally located wound. In a similar fashion as above, another 9–0 polypropylene suture was used to loop the second fixation hole with a Girth Hitch knot. This pair of polypropylene sutures were externalized via the wound through the 350-degree (nasal) Hoffman pockets using a bent 27-gauge needle (Figure 6). The pair of polypropylene sutures threaded through the superior nasal paracentesis were then externalized through the 170-degree (temporal) Hoffman pocket in a similar fashion (Figure 7). All 4 sutures were tightened to center the lens in the sulcus and tied down with the knot buried in the Hoffman pockets. The limbal wound was closed with 2 interrupted 10–0 nylon sutures.

Figure 6.

Transferring a CTC6L needle with attached polypropylene sutures via a 27-gauge needle to the 350-degree Hoffman pocket from the inferotemporal wound.

Figure 7.

Transferring sutures via a 27-gauge needle to the 170-degree Hoffman pocket from the nasal paracentesis.

At 1 month postoperatively the patient’s best-corrected vision was 20/30+1 with a manifest refraction of −1.75+2.00×040. The toric lens was centered behind the iris and aligned at 159 degrees. The residual astigmatism was thought to be due to the tight sutures placed in the inferotemporal wound, which were cut at this visit. The patient failed to return to our clinic for further follow-up.

Discussion

Displaced IOLs are an unfortunate complication of cataract surgery and can occur months to years after the original surgery.⁵ As more suturing techniques are being reported, IOL exchange rates have been decreasing in favor of simply repositioning the dislocated lens.⁹ Various techniques have been utilized to optimize repositioning of dislocated plate haptic IOLs,^2–6 but very few techniques have been described for plate haptic toric IOLs specifically.¹⁰ Moreover, none have described how to correct a displaced in-the-bag plate haptic toric IOL located posterior to the iris from the perspective of an anterior segment surgeon. We describe a technique that successfully placed the IOL in proper position and resulted in good vision for the patient.

Firstly, we created a safety basket using 2 10–0 polypropylene sutures to form a grid behind dislocated IOL.⁷ This helps ensure the safe retrieval of the IOL, as most anterior segment surgeons are ill-equipped to retrieve an IOL that has dislocated beyond anterior vitreous.

Secondly, passing sutures inside the eye through fixation holes for the plate haptic IOL poses unique problems for the anterior segment surgeon. The overall length of most plate haptic IOLs is 9.8–10.9 mm. In order to pass the suture through the fixation hole, one must tilt the IOL at an angle with the other end of the haptic in the midvitreous (Figure 8). Then the needle and the entire IOL is lowered in the anterior vitreous to facilitate the retrieval of the needle in the ciliary sulcus through the scleral wall (Figure 9). Unless this suture is tied using a modified Siepser sliding knot technique,¹¹ there is a risk of losing the hold on the fixation hole, and thus the IOL, as the trajectory of the needle generally has a downward slope. This is relatively easy for a vitreoretinal surgeon, as the standard 3-port posterior vitrectomy allows holding the IOL in the vitreous via any of the sclerostomies. In addition, should the IOL posteriorly dislocate to the retina, the retina surgeon can refloat and regrasp the IOL, which is not the case for anterior segment surgeons. Most anterior segment surgeons are not comfortable making sclerostomies or using retinal forceps to hold an IOL within the vitreous cavity. Additionally, a vitrectomy would be needed if the IOL posteriorly dislocates, and the anterior segment surgeon would be ill-fitted to retrieve it safely. To avoid these potential problems, we chose to tie the haptic by temporally externalizing the fixation hole through a small limbal incision. This allowed us to securely fix the haptic quickly while the IOL was parallel to the iris surface, avoiding potential problems of vitreous prolapse as well as further dislocation of the IOL into the vitreous cavity.

Figure 8.

The intraocular lens must be tilted at an angle to pass sutures through the fixation hole within the eye.

Figure 9.

Illustration of position and angle of plate haptic intraocular lens for haptic to be sutured through the scleral wall.

Thirdly, we were able to place the suture in a predetermined meridian in order to align the plate haptic toric IOL and to neutralize corneal astigmatism. The scleral fixation sites were premarked, and the sutures were guided out by docking the long CTC6L needle into the hollow 27-gauge hypodermic needle. Redirection of the suture in the anterior chamber was achieved by docking the long CTC6L needle into the hollow 26-gauge long cannula, which was retrieved via a paracentesis (Figure 5). This combination of techniques allows for scleral fixation in any meridian, and there should there be no other limitations (i.e., trabeculectomy).

WHAT WAS KNOWN

• Reports of repositioning plate haptic IOLs have been described; however, available descriptions do not address how to specifically reposition a plate haptic toric lens, especially from the perspective of an anterior rather than posterior segment surgeon.

WHAT THIS PAPER ADDS

• We present an approach to specifically address repositioning a plate haptic toric lens and detail specific steps to prevent the lens from falling to the back of the eye from the anterior segment surgeon’s perspective, such as using a safety suture grid as well as safely guiding and retrieving suture with hypodermic needle or cannula.