TROCAR BLADE-assisted scleral fixation for dislocated iol

TROCAR BLADE-assisted scleral fixation for dislocated iol

1. Trocar blade-assisted scleral fixation for an incomplete dislocated intraocular lens MODERATOR – DR ASHWINI KV PRESENTER- DR APOORVA N

2. INTRODUCTION  Many techniques for the management of in-the-bag intraocular lens (IOL) dislocation and subluxation have been described.   A specific intermediate situation was described as trapdoor-like dislocation where the zonular fibers are severely, but not completely, disrupted. The IOL would dangle in the vitreous cavity with the remaining zonular fibers acting like the hinge of a trapdoor. Hayashi et al. described a maneuver to retrieve the IOL by pushing the IOL to the posterior chamber with a pick placed through a pars plana-set trocar at where the zonular fibers remain, and the IOL can be accessed anteriorly and removed through a corneal incision for IOL exchange.

3. This study is the modified procedure described by Hayashi et al. for retrieving an incomplete posterior dislocated IOL. By using a trocar blade to lift and stabilize the IOL at the ciliary sulcus, the IOLs were fixated in situ using a simple ab externo scleral suture loop fixation technique described by Chan et al., which was originally limited to patients with decentered IOL.

4. SURGICAL TECHNIQUE A trocar was set at the pars plana of the area where the zonular support remained. Instead of removing the trocar blade after placing , the trocar blade was kept and turned, with the tip of the blade pointed toward the center of the pupil (Figure 1 ).

5. This maneuver lifted the IOL by the shaft of the trocar blade toward the pupillary plane. The shaft of the trocar blade can be left laying parallel to the pupillary plane with the tip pointing toward the pupil center by having an assistant gently support the handle of the blade or with the support of the orbital rim if the trocar was at the nasal quadrant.

6.  A paracentesis was created at the opposite side of the cornea to where the haptic needed to be fixated. Viscosurgical agents were used to maintain the anterior chamber. The haptics were fixated using the haptic loop method after creating a small peritomy. A straight needle with a 10-0 polypropylene suture entered the eye at 2.5 mm from the limbus where the haptic– bag complex was to be fixated. The needle passed under the haptic then perforated the posterior capsule anteriorly near the haptic. Subsequently, the needle exited the eye from the side port by docking into a 27-gauge needle.

7.  The trocar blade could now be replaced by infusion for maintaining the intraocular pressure (IOP). However, the infusion was kept off during IOL fixation to prevent  turbulence causing further damage to the remaining zonule. The straight needle reentered the eye through the side port then exited the eye by docking into a bent 27-gauge needle that entered 1.5 mm from the limbus near the first entry.

8. A 3-1-1 knot was carefully tied loosely and rotated into the eye to prevent erosion of conjunctiva. A Sinskey hook was used to create a counter force to stabilize the IOL if stress to the zonule was found during knot rotation. Standard pars plana vitrectomy was performed if the eye was not previously vitrectomized .

9. Ophthalmic viscosurgical devices were removed. Finally, the infusion cannula was removed, and the conjunctiva was sutured to cover the stitch. The details of the surgical procedure were subject to change according to the patient’ s specific condition.

10. The results of 4 cases that received scleral fixation using this technique (Table 1 ). All patients received the surgery under retrobulbar anesthesia . All had significantly improved visual acuity . No surgical complications were encountered. Individual information regarding each patient is provided in Table 1 . The details of 2 representative cases are presented below.

11. Case 1: Nonvitrectomized Eye An 86-year-old woman with dementia had subluxation of the IOL in her right eye. Preoperative visual acuity-CF. The IOL appeared to be inferiorly subluxated under slitlamp examination. However, under surgical microscope, the IOL became vertical in the vitreous cavity when the patient was in a supine position . The sector capsular bag with zonular attachment was found at the inferior nasal quadrant, so an additional trocar was set at this sector.

12.  The trocar blade was used to lift up the IOL, and the posteriorly dislocation haptic was displaced into the AC with a Sinskey hook. The haptic was fixated using the loop method with a 10-0 polypropylene suture looping the haptic– bag complex. Pars plana vitrectomy was performed after the fixation to prevent any residual vitreoretinal traction. The IOL was well centered and well leveled with the iris plane after surgery. Corrected distance visual acuity improved to 6/12 three months after surgery.

13. Case 2: Previously Vitrectomized Eye A 64-year-old man complained of blurred vision of the left eye after blunt trauma. He had received pars plana vitrectomy 1 year prior. His uncorrected distance visual acuity was 6/12. Slitlamp examination showed the IOL to appear to be subluxated laterally. During the surgery, a trocar was placed at the pars plana at the 4 o’clock position; then, the IOL–bag complex was lifted and stabilized at the ciliary sulcus with the trocar blade throughout the surgery. The haptic–bag complex was fixated at 11 o’clock with a 10-0 polypropylene suture. The postoperative uncorrected distance visual acuity was 6/6 one week after surgery.

14. DISCUSSION Masket et al described the concept of pars plana stabilizing a subluxated IOL for fixation using a polypropylene suture. We simplified the procedure by using the trocar blade that is used routinely for trocar insertion during vitrectomy. The IOL was elevated from the vitreous cavity and maintained in the sulcus position for suture fixation.

15.  Our maneuver combined the ab externo loop fixation technique described by Chan et al., which was indicated for cases of IOL decentration.   The benefit of this technique is that it can easily be performed at any quadrant of the eye, in contrast to other techniques that involve creating a scleral flap or pocket, which would be slightly difficult for some quadrants of the eye, and so the IOL and remaining zonular fibers can be preserved.

16.  ADVANTAGE- 1)the instrument is readily available in most operating rooms that perform vitreoretinal surgery. 2)the maneuver is easy and intuitive. 3)the trocar blade can serve as an extra hand to stabilize the IOL in the sulcus position throughout the process of scleral fixation. 4)it is safe to use. The built-in stopper of the blade prevents the blade from going further into the eye, so it is very unlikely to cause any intraocular damage unless the tip of the blade is pointed away from the cornea, then because the shaft of the blade would be blocking the surgical view in this scenario.

17. The shaft of the blade is parallel to the IOL when it provides support to the IOL and the tip of the blade does not contact with the IOL. We have not found any damage to the eye or the IOL caused by the trocar blade. AVOIDED FACTORS First is to avoid turbulence in the eye while fixating the IOL. Having an active infusion while the needles pass through the side port will inevitably cause a turbulence in the eye that may result in further damage to the remaining zonule. To avoid turbulence, we had the infusion turned off while the needles passed through the side ports. On the other hand, maintaining the eye pressure is also important to prevent damage caused by hypotony, especially while having the trocar blade inside the eye.

18.  To maintain the IOP, we filled the AC with Ophthalmic viscosurgical devices and turned on the infusion from time to time when the IOP became low. If the trocar was occupied by the trocar blade, balanced salt solution was injected into the AC through side port. ADV decreasing the turbulence -1)lowers the potential damage to the corneal endothelium. 2) It is important to not perform complete vitrectomy at the beginning of the surgery. If the vitreous herniation into the AC or the sulcus is of concern in that vitreous traction may be caused during IOL fixation, a limited vitrectomy may be performed prior to the IOL manipulation to prevent retinal tear or detachment.

19.  This technique can an also be used in conditions where the surgical plan is to retrieve the IOL in the AC for IOL exchange. Using this technique, the IOL can be stabilized at the sulcus and the surgeon can displace the haptics into the AC with a Sinskey hook or spatula. limitation only short-term results were reported. The 10-0 polypropylene suture has recently been considered to be related to long-term breakage.   Longterm follow-up of these patients is needed to evaluate the stability of the IOL.

20. CONCLUSION In summary, we found using a trocar blade to assist scleral fixation to be a helpful and safe technique with good visual outcome for the treatment of an incomplete dislocated IOL.

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