Trans pars plana safety basket suture helpful in malpositioned IOL cases

The completed suture path appears similar to a tic-tac-toe board that acts as a scaffold posterior to the IOL.

Issue: September 10, 2016

BySamuel Masket, MD

ByNicole R. Fram, MD

The reported occurrence of IOL dislocation after cataract surgery varies from 0.05% to 1.8%. Surgical correction of malpositioned IOLs can be challenging even for the most experienced cataract surgeon. A complete clinical evaluation, including a detailed history, and a dilated exam are essential parts of the decision-making process as to whether or not to surgically intervene in a particular case. It is important to have the patient lie flat and assess the extent of posterior IOL fallback in the supine position.

In some mild IOL malposition cases, pharmacologic pupillary manipulation may suffice, while in other cases, surgical intervention may be needed to relieve the patient’s symptoms.

When surgical intervention is chosen for the correction of a malpositioned IOL, the surgeon has to select between an open-technique or a closed-technique for the repositioning or exchange of the IOL. The surgical technique is tailored to the individual case depending on how much residual support tissues are available, the status of the IOL (normal vs. damaged or opacified) and the surgeon’s comfort level. The malpositioned IOL may be stabilized and fixated to the iris or sclera with or without sutures, as in the scleral pocket technique. One of the important considerations is not to accidentally drop the IOL into the posterior vitreous cavity during surgery.

In this column, Drs. Masket and Fram describe their technique of a safety basket suture to provide added safety during surgical management of malpositioned IOLs.

Figure 1. Completed basket safety suture noted by arrows. Two horizontal mattress sutures are passed across the pars plana beneath the IOL to act as a scaffold during repositioning or removal and replacement of the IOL.

Figure 2. Straight suture needle is bent approximately 15° with needle holders approximately 3 mm to 4 mm from the sharp end of the needle.

Figure 3. The safety suture is initiated in the horizontal meridian 2.5 mm to 3 mm posterior to the limbus. The suture needle (above) and the 27-gauge hypodermic needle are 180° apart at the opposing limbal regions. Note the marked zonulopathy and IOL subluxation in this eye that has had prior pars plana vitrectomy and scleral buckling. Conjunctival scarring is evident.

Figure 4. The suture needle has been docked (arrow) into the 27-gauge hypodermic needle posterior to the IOL/capsule bag complex. The 27-gauge needle has been bent near the hub, which is visible in the lower part of the photo.

Figure 5. Once the first basket suture has been completed in the horizontal meridian, the process is repeated in the vertical meridian.

Figure 6. Once the basket safety suture is completed, the IOL/capsule bag complex is suture fixated to the sclera by a lasso suture passed around the IOL loops with 10-0 polyester suture (PC-7 needle, Alcon). A 25-gauge needle has been passed through the Hoffman pocket and penetrates the capsule bag beneath the haptic, and the suture is brought through an opposing paracentesis. Note the 23-gauge anterior chamber maintainer.

Figure 7. The lasso suture is completed for the nasal IOL loop with the passage of the suture in front of the IOL loop. The needle is docked into a 25-gauge hypodermic needle passed through the Hoffman pocket into the eye on top of the capsule bag (arrow).

Figure 8. At the completion of surgery, the safety sutures have been removed, and the IOL is well-centered and stable.

Thomas “TJ” John, MD
OSN Surgical Maneuvers Editor

Late malpositioned IOLs are becoming increasingly common. A number of risk factors are evident, among them pseudoexfoliation and history of pars plana vitrectomy. In the repair of malpositioned IOLs, a strong concern of the anterior segment surgeon is loss of the IOL into the posterior segment at some point during surgery. This problem is particularly noteworthy in post-vitrectomy cases, in which the IOL may fall precipitously onto the retinal surface, absent the buoyancy of the vitreous.

In order to preclude that possible complication, we have devised a safety basket suture method — sometimes referred to as the “Masket basket” — that consists of a trans pars plana double horizontal mattress suture of 10-0 polypropylene. As can be noted in Figure 1, the completed suture path appears similar to a tic-tac-toe board that acts as a scaffold posterior to the IOL. The technique, described below, has been published in the Journal of Cataract and Refractive Surgery. We have employed the method in nearly 100 cases, and to date the only complication is rare minor vitreous hemorrhage that may accompany any perforation of the pars plana. Given that the majority of cases have been in eyes after vitrectomy, a rare vitreous hemorrhage clears rapidly. Moreover, we have observed no problems associated with vitreoretinal traction, although this must be considered when using the technique in eyes that have not been subjected to prior pars plana vitrectomy. In such cases, often a single mattress suture, or “half basket,” may suffice.

Tools

A 10-0 polypropylene suture on a straight long needle (STC-6, Ethicon) is the suture material of choice; the needles are deliberately bent approximately 15° and 3 mm to 4 mm from the sharp end (Figure 2). This allows the needles to be firmly docked by friction at the bend of the 10-0 polypropylene needle into a 27-gauge short disposable needle that is also bent, but near its hub. An anterior chamber trocar or maintainer or a pars plana trocar infusion system is needed to maintain adequate IOP during surgery. It may be placed before or after the basket safety suture. It is often easier to place the safety basket sutures before making corneal or scleral incisions because the eye is fully pressurized.

Technique

The bent suture needle and angled 27-gauge hypodermic needle are aligned 180° apart in the same meridian approximately 2.5 mm to 3 mm posterior to the limbus (Figure 3). When working horizontally, care is taken to avoid the 3 o’clock to 9 o’clock meridian to preclude puncturing the long ciliary vessels and inducing major intraocular bleeding. The two needles pierce the pars plana underneath the IOL 180° apart and are docked together. The suture needle is advanced past the angulated portion to assure a solid dock in the hypodermic needle (Figure 4). The two needles are withdrawn as one from the globe. The surgeon must confirm the two needles are fully docked and moving as one unit before retrieval out of the eye. The second arm of the double-armed 10-0 polypropylene suture is then passed in the same way, separated from the first pass by approximately 3 mm to 4 mm. Once the two suture arms are passed, they are tied, creating a horizontal mattress suture. The procedure is repeated in the opposing meridian if there is significant lens instability (Figure 5).

Once the “safety basket” suture has been completed, the surgeon has the option of retaining the IOL and fixating it to the iris or sclera in a preferred manner; alternatively, it may be exchanged. In the case at hand, we opted to retain the three-piece IOL and suture fixate it to the sclera with 10-0 polyester suture via Hoffman scleral pockets (Figures 6 to 8). After the IOL is repositioned and secured, the safety basket sutures are cut and removed from the eye. Peripheral retinal examination should be performed on the surgical table or in the early postoperative period.

References:
Hoffman RS, et al. J Cataract Refract Surg. 2006;doi:10.1016/j.jcrs.2006.05.029.
Lichtinger A, et al. Int Ophthalmol. 2013;doi:10.1007/s10792-012-9635-0.
Masket S, et al. J Cataract Refract Surg. 2013;doi:10.1016/j.jcrs.2013.08.038.
Smith SG, et al. J Am Intraocul Implant Soc. 1985;doi:10.1016/S0146-2776(85)80139-7.
Stark WJ Jr, et al. Trans Am Ophthalmol Soc. 1983;81:280-309.

For more information:
Samuel Masket, MD, a clinical professor at Jules Stein Eye Institute, UCLA, can be reached at 2080 Century Park East, Suite 911, Los Angeles, CA 90067; email: avcmasket@aol.com.
Nicole R. Fram, MD, a clinical instructor at Jules Stein Eye Institute, UCLA, can be reached at 2080 Century Park East, Suite 911, Los Angeles, CA 90067; email: avcweb@aol.com.
Edited by Thomas “TJ” John, MD, a clinical associate professor at Loyola University at Chicago and in private practice in Oak Brook, Tinley Park and Oak Lawn, Ill. He can be reached at email: tjcornea@gmail.com.

Disclosures: Masket, Fram and John report no relevant financial disclosures.