Unintended postoperative refractive and optical outcomes are a major source of dissatisfaction in cataract surgery patients expecting refractive results near emmetropia and relative independence from spectacles. Further surgical intervention may be required. One option is an intraocular lens (IOL) exchange. Incorrect IOL power calculation,1–3 optical aberration, dislocation and decentration, incorrectly labeled IOL power,4,5 and delayed calcification and opacification6–8 are the potential indications for an IOL exchange. Studies have depicted intraoperative complications such as zonular dialysis, posterior capsule rupture, and iridodialysis in approximately 30% of exchange cases,9–11 reflecting the technical difficulty of the IOL exchange procedure. In some cases, a neodymium:YAG (Nd:YAG) laser capsulotomy may have been performed, further complicating an IOL exchange.
Various techniques have been devised to decrease the incidence of intraoperative complications in IOL exchange, such as removing the optic only, leaving the firmly adhered haptics in the bag.12 Methods for removing a foldable IOL through a small incision include transecting it with a cutting instrument or refolding the IOL in the anterior chamber and removing it intact with the folding instrument.13–15 However, development of a posterior capsule rupture intraoperatively has been reported when the optic is being divided for removal through a small incision.12
We describe a surgical technique that can solve the issue of posterior capsule rupture during the process of sectioning the optic with scissors and/or prevent vitreous prolapse when the posterior capsule is open prior to the IOL exchange. The IOL scaffold16,17 has been used in cases of posterior capsule rupture in which the IOL is inserted below the nonemulsified nuclear fragments; the IOL acts as a barrier or scaffold, creating an artificial posterior capsule and preventing the slippage of any nuclear material into the posterior chamber, facilitating safe emulsification in the anterior chamber. In this technique, after the offending IOL is elevated into the anterior chamber from the bag, a corrective IOL is injected into the bag and the original IOL is removed.
Before surgery, the pupil is dilated with tropicamide and phenylephrine hydrochloride 2.5%. A peribulbar nerve block (50:50 mixture of lidocaine 2.0% and bupivacaine hydrochloride 0.75% with hyaluronidase) is injected. A previously created corneal incision is opened if the prior surgery is recent; otherwise, a fresh incision is created in a different location. The anterior chamber is filled with an ophthalmic viscosurgical device (OVD) through the same tunnel (Figure 1, A). The OVD is injected beneath the IOL optic; the capsular bag is safely dissected and separated from the IOL surface using standard techniques. After some protection of the posterior capsule is obtained, the hook and dialers are used to gently lift the IOL and manipulate it out of the bag (Figure 1, B and C). The IOL is pushed slightly to the opposite side so the haptics can be easily removed from the bag. In cases in which the haptic end cannot be freed from the capsule equator, the haptic is cut as far in the periphery as possible using coaxial-action microscissors. A corrective IOL is loaded and injected beneath the previous IOL and dialed into the bag (Figure 1, D). The new IOL acts as a scaffold when the offending IOL is cut, preventing damage to the posterior capsule; in cases in which the posterior capsule is open, the new IOL acts as a barrier to vitreous prolapse. A specially designed Chang-Packer scissor can be used to cut the IOL, while a microforceps (Microsurgical Technology) is used to grab the IOL. The anteriorly elevated IOL is cut (Figure 2, A) with scissors along its longitudinal axis, which is then rotated 180 degrees and a second cut is made along the same axis to eventually cut the IOL into 2 pieces. Each cut fragment of the IOL is then explanted sequentially (Video 1, available at http://jcrsjournal.org). In cases with an open posterior capsule, placement of a 3-piece IOL in the sulcus with optic capture in the capsulorhexis margin can also be considered. The OVD is aspirated and/or irrigated from the eye, and the corneal incision is sealed by hydrating the corneal stroma (Figure 2, B) or using a suture as needed.
The IOL scaffold technique was used in 12 cases: 6 were IOL exchanges from an intact capsular bag, 4 were IOL exchanges with an open posterior capsule from a primary operative complication or postoperative Nd:YAG laser posterior capsulotomy, and 2 were during primary cataract surgery in which the initially implanted IOL was recognized to be damaged and required immediate IOL exchange.
The time interval between the primary surgery and IOL exchange was short; in most cases, the procedure was done within the first few postoperative days. In all cases, the IOL was released from the capsular bag and a new acrylic IOL safely implanted in the bag without extra manipulation. The IOL exchange procedure was uneventful in all cases; no complications were encountered and all patients had good vision after surgery.
In cases involving IOL exchange from a capsule-fixated IOL many months or years postoperatively, the surgeon was able to open the capsular bag successfully and use the scaffold technique to protect the posterior capsule or avoid vitreous prolapse if the posterior capsule was open. Care was taken while dialing the IOL haptic out of the capsular bag to avoid undue stress on the capsule. No case of zonular dehiscence, iatrogenic posterior capsule rupture, or vitreous prolapse was seen.
The phrase “wrong eye, wrong intraocular lens, wrong patient”18 summarizes the entire saga of a postoperative refractive surprise and disappointment. Inaccurate IOL power prediction and patient dissatisfaction with the optical performance of the original IOL account for the majority of cases.18 Meticulous preoperative workup helps to identify the solution for many of these issues. In rare cases in which no reason for a significant refractive surprise can be identified, an incorrectly labeled IOL must be considered a potential cause of the unintended refractive outcome.4,5
Yu and Shek6 report 2 cases of posterior capsule rupture and 3 zonular dehiscences in a series of 15 IOL exchange surgeries for calcified IOLs. Gashau et al.10 report a 23.1% occurrence rate of vitreous loss necessitating anterior vitrectomy. While many effective techniques for IOL exchange exist,15,19–24 including intraocular folding, bisection, trisection, and other cutting methods, we prefer the IOL scaffold technique for its technical ease in our hands. The technique bisects the foldable IOL and does not necessitate enlarging the corneal incision; it also prevents accidental damage to the posterior capsule during the process of transection of the IOL and prevents vitreous prolapse if the posterior capsule is open. The IOL scaffold has been used in cases with posterior capsule rupture with remnant nucleus that has yet to be emulsified.16,17 The scaffold technique described here further extends application in reducing potential complications of IOL exchange.
The technique does not require specially designed instruments. During optic transection, the stability of the IOL optic is important to prevent the optic from slipping and inadvertently damaging the ocular tissues, including the posterior capsule. Preinsertion of a corrective IOL into the bag acts as a support and a scaffold during the process of transection, preventing optic slippage and safeguarding the posterior capsule. This method involves the simultaneous presence of 2 IOLs inside the eye and is applicable in all cases in which the offending IOL can be safely manipulated from the capsular bag into the anterior chamber. Another advantage of this technique is the issue of pupillary miosis that is common with segmenting and manipulating the original IOL out of the eye. This makes the insertion of a corrective IOL more difficult due to concealment of the capsulorhexis margin that precludes proper in-the-bag placement of an IOL. Preinsertion of an IOL as described in this technique helps to prevent this scenario.
Meticulous separation of the IOL from the capsular bag with OVD followed by prolapsing the IOL into the anterior chamber and inserting a fresh IOL into the bag are key to the success of the procedure. Although the pieces with attached haptics may be slightly larger, their flexibility allows them to be withdrawn easily with virtually no deformation as they pass through the wound. Although no specific tests were done to analyze the endothelial loss, postoperative clarity of all corneas indicated a lack of endothelial trauma. We do not recommend this procedure in eyes with shallow anterior chambers because of the increased manipulation in a limited space and a concern for endothelial cell loss. Some authors remove the IOLs through 6.0 mm incisions without folding or cutting them to minimize endothelial cell damage.9
With our technique, we did not have to enlarge the corneal incision to facilitate explantation of the transected IOL. Nevertheless, attention should be paid to possible adhesions between the IOL haptic and the capsule. In eyes with an open posterior capsule, although a 3-piece IOL can be placed in the sulcus, we did not have to use this option as no frank vitreous prolapse was seen. All IOLs were placed in the bag. Complications such as posterior capsule rupture and zonular dehiscence were not observed in any case, which can be attributed to the explantation of an IOL within a short time of initial surgery. Although there is a potential risk for damaging the anterior surface of the corrective IOL with the cutting scissors, this complication did not occur. In summary, this technique seems to be a viable option in patients with visual complaints attributable to an IOL power surprise or dissatisfaction with the optical performance of the IOL.
What Was Known
- Damage to the posterior capsule and/or vitreous prolapse through an open posterior capsule is a known complication of IOL exchange.
- The IOL scaffold is a technique used in cases of posterior capsule rupture with remnant nonemulsified cortical and nuclear fragments.
What This Paper Adds
- The IOL scaffold technique involves simultaneous presence of 2 IOLs in the eye; the new IOL acts as a scaffold or armor for the posterior capsule during the removal of the original IOL in the anterior chamber, preventing inadvertent damage to the posterior capsule or vitreous prolapse when the posterior capsule has been opened.
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Video 1 The technique of IOL scaffold abetting the IOL exchange procedure in a case with postoperative refractive surprise. The anterior chamber is filled with dispersive OVD to coat the endothelium. The IOL is meticulously lifted from the bag and is prolapsed into the anterior chamber. The capsular bag is inflated with OVD, and a new corrective IOL is loaded and injected beneath the previous IOL. The corrective IOL is dialed into the bag. The original IOL in the anterior chamber is cut with IOL cutting scissors. The corrective IOL in the bag acts as a scaffold for the posterior capsule and prevents both optic slippage and inadvertent damage to the posterior capsule during the process of optic transection. The cut pieces of the IOL are then explanted, and stromal hydration of the corneal incision is performed.