Scleral Suture-Fixation Technique for One-Piece Acrylic Intraocular Lens

Abstract

Purpose

To describe a previously published scleral-fixation technique to secure one-piece acrylic intraocular lenses (IOLs) to the sclera.

Methods

Retrospective, consecutive, non-comparative case series.

Patients

16 eyes of 15 patients

Results

All patients who underwent scleral-fixation of one-piece acrylic IOLs using the loop method from 2014 to 2016 were included. The mean follow-up was 8.1 months. The dislocated one-piece acrylic IOL was repositioned in 8 eyes, a primary implantation was performed in 5 eyes, and the IOL was exchanged in 3 eyes. All IOLs remained well-centered postoperatively. The vision improved from an initial best corrected visual acuity of 0.97 ± 0.74 logMAR (Snellen equivalent ≈20/190) to 0.47 ± 0.49 logMAR (≈20/60, P=0.031) at the last follow-up. The post-operative complications were self-limited.

Conclusions

The previously reported scleral suture-fixation technique can be readily applied to one-piece acrylic IOLs.

Introduction

Acrylic one-piece posterior chamber intraocular lenses (PCIOLs) are some of the most commonly implanted lenses. Trauma, pseudoexfoliation, or zonular dehiscence, however, may dislocate the IOLs. Fixating IOLs without adequate capsular support presents a challenge. While exchanging the dislocated lens for an anterior chamber IOL (ACIOL) or sulcus IOL remains an option, it requires a large incision and risks corneal endothelial cell loss.¹ Newer techniques like externalizing the haptics of a three-piece IOL cannot be applied to most one-piece PCIOLs.²

The purpose of the current case series is to demonstrate the adaptability of a previously established scleral suture-fixation technique to one-piece acrylic PCIOLs.

Methods

Patients at the Bascom Palmer Eye Institute who underwent scleral suture-fixation of one-piece acrylic PCIOLs from 2014–2016 by one author (WS) were included; the IOLs were the Tecnis ZCB00 (Abbott Medical Optics, Santa Ana, CA), AcrySof SN60WF (Alcon, Fort Worth, TX), and AcrySof SN6AT. Exclusion criteria included less than 1 month of follow-up examinations. The study was approved by the institutional review board of the University of Miami Miller School of Medicine and was compliant with the Health Insurance Portability and Accountability Act of 1996. The research adhered to the tenets of the Declaration of Helsinki. The logMAR equivalents of the Snellen visual acuities were used for calculating the student’s t-test.

The same scleral suture-fixation technique was performed in all patients but was modified slightly depending on whether the IOL was repositioned or secondarily implanted. The technique has been previously reported in detail, but the key elements included performing a pars plana vitrectomy, creating two partial thickness scleral flaps 180 degrees apart, threading two 9-0 polypropylene sutures through two 27-gauge needles, passing the sutures and needles through the scleral beds 1.5mm posterior to the limbus, grasping the dislocated IOL with 20-gauge intraocular foreign body forceps, looping the haptics with the sutures, tying a square knot to secure the IOL, suturing to the episclera, and tying another square knot under the scleral flaps (Figure). When the IOL was secondarily implanted, the polypropylene sutures were retrieved through clear corneal incisions and secured around the haptics before implanting the IOL and completing the scleral fixation step as described for repositioning.

Figure. Scleral Suture-Fixation Technique for a Dislocated One-Piece IOL.

A) After a conjunctival peritomy and a pars plana vitrectomy were performed, two scleral flaps were created 180 degrees part. B) Two 9-0 polypropylene sutures were passed through two 27 gauge needles. C) The needle with suture was inserted 1.5mm posterior to the limbus in the scleral bed. The IOL was grasped with intraocular forceps. The polypropylene suture was looped around the haptic. D) A square knot secured the suture to the haptic. E) The suture was then passed through the episclera, and a second square knot was made. F) The suture ends were trimmed and covered with the scleral flaps. The same procedure was repeated to secure the other haptic. The conjunctiva was then closed.

Results

A total of 16 eyes in 15 patients was included. The mean age was 62 years old (range: 25–90); eleven patients were males (73%), and 7 (44%) were right eyes. The mean follow-up interval was 8.1 months (range: 1.5–20 months). The past ocular histories included glaucoma (4/16, 25%), amblyopia (3/16, 19%), retinal detachment and macular hole repair (RD and MH, 1/16, 6%), branch retinal vein occlusion (BRVO, 1/16, 6%), and acute retinal necrosis (ARN, 1/16, 6%).

The patients were divided into three groups: those who had repositioning of their dislocated IOLs (8 eyes), those who received secondary IOLs (5 eyes), and those whose pre-existing IOLs were exchanged for one-piece PCIOLs (3 eyes). In the first group, four eyes had traumatically dislocated IOLs (including two toric IOLs), two had pseudoexfoliative glaucomas, and two had zonular dehiscences. In the second group, pars plana lensectomies were performed for three dislocated crystalline lenses, and two eyes were aphakic after congential cataract surgeries. In the third group, one patient had a broken haptic, one had plate-style haptics, and one ACIOL had caused uveitis-glaucoma-hyphema syndrome.

The mean best corrected visual acuity at the initial presentation was 0.97 ± 0.74 logMAR (Snellen equivalent≈20/190), and the mean vision at the last examination was 0.47 ± 0.49 logMAR (≈20/60, P=0.031). There were no statistically significant postoperative changes in the spherical equivalent (initial: +2.20 ± 6.2 diopters (D), final: +1.10 ± 0.49D, P=0.11) or astigmatism (−0.40D, P=0.37). The two patients with toric IOLs had no significant shifts in their astigmatic axes or powers.

Postoperative complications included self-limited vitreous hemorrhages (2/16, 13%); one patient had a prior BRVO and another had ARN previously. Two patients had non-visually significant epiretinal membranes (13%); one had prior trauma, and another had a previous RD and MH. One patient had an exposed suture tail that was trimmed. In another patient, the haptic appeared to have been amputated by the polypropylene suture; the patient underwent a scleral fixation with another one-piece PCIOL and developed no further complications in 18 months of follow-up.

Discussion

Inadequate posterior capsular support prevents standard implantation of a posterior chamber IOL in some patients. Many existing techniques, however, cannot be applied to one-piece acrylic IOLs and may require an IOL explantation or exchange. The current study demonstrates the applicability of a previously described scleral suture-fixation technique to one-piece acrylic IOLs. The PCIOLs remained well-centered without statistically significant refractive changes postoperatively. There were no permanent, visually significant postoperative complications. The square edge haptics and terminal flares helped to prevent the sutures from sliding off the lenses and provided greater contact area for IOL stability compared to three-piece IOLs. Further stabilization was provided by the two square knots used to secure the suture to the IOL and to the sclera. The overall visual results were good but were limited in some cases by the underlying past ocular histories, including glaucoma and amblyopia.

Additional benefits of the described technique include minimizing the number and size of ocular incisions and avoiding the incumbent trauma that IOL exchanges with rigid lenses entail. Furthermore, the procedure required no specialized, expensive equipment; the two 27-gauge needles cost less than 10 cents and the polypropylene suture less than $15. The entire procedure was relatively quick to perform, minimizing operating costs and the risk of microscope light-induced photoxicity.³

The limitations in the study include the small number of cases, relatively short follow-up, and retrospective nature; however, the same technique has been applied to three-piece IOLs and followed for many years with similar success.⁴ Although a 20-gauge incision was used to accommodate the IOL forceps, smaller 23-gauge forceps could be used. A disadvantage of the described scleral suture-fixation technique, like many other methods, is that it cannot be applied to plate-style haptics.

In conclusion, the scleral suture-fixation technique is a versatile surgical technique that can result in good visual outcomes in patients with dislocated one-piece acrylic intraocular lenses.

Summary Statement.

The described surgical technique can fixate the popular one-piece acrylic intraocular lenses to the sclera.