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SILICONE MICROTUBE–ASSISTED SCLERAL FIXATION OF A POSTERIOR CHAMBER INTRAOCULAR LENS

Kataoka, Takuya, MD, PhD; Kamei, Motohiro, MD, PhD

doi: 10.1097/IAE.0000000000002143
Original Study

Purpose: To report a novel technique for intrascleral fixation of a posterior chamber intraocular lens using a silicone microtube to manipulate the haptics into position.

Methods: Intrascleral fixation was performed in six eyes and the results evaluated in this retrospective case series. A silicone microtube with a 0.2-mm external diameter was passed from a sclerocorneal incision through the chamber and a sclerotomy made using a 30-gauge needle. The tips of the intraocular lens haptics were connected to the silicone microtube outside the eye. After the intraocular lens was injected into the posterior chamber, the haptics were drawn through the scleral incision through their attachment to the silicone microtube.

Results: The mean postoperative corrected visual acuity was 0.62 logarithm of the minimum angle of resolution (20/43) with a mean refraction error of −0.06 ± 0.4 diopter, which did not differ significantly (P = 0.53) from the expected value. The postoperative complications included transient ocular hypotension, vitreous hemorrhage, and choroidal detachment.

Conclusion: Our technique using a silicone microtube reduces the number of intraocular procedures compared with previous methods using forceps or needles for moving the intraocular lens haptics from the posterior chamber to the outside through sclerotomies.

A technique using silicone microtubes to achieve scleral fixation of posterior chamber intraocular lenses facilitates easier and fewer intraocular procedures compared with previous methods requiring use of forceps or needles to manipulate the haptics into position.

Department of Ophthalmology, Aichi Medical University, Nagakute, Japan.

Reprint requests: Motohiro Kamei, MD, PhD, Department of Ophthalmology, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan; e-mail: motokamei@aichi-med-u.ac.jp

Presented in part at the 20th Duke Advanced Vitreous Surgery (AVS) Course at Durham, NC, April 22, 2017.

None of the authors has any financial/conflicting interests to disclose.

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Intrascleral (or scleral) fixation of a posterior chamber intraocular lens (IOL) has been reported recently as a method of secondary implantation for cases with aphakia or IOL dislocation.1–15 The methods have been modified and improved since 2007 when Gabor and Pavlidis first reported their technique of fixing IOL haptics in a scleral tunnel created using a 24-gauge needle.1 With better centering and less tilting of the IOL, this procedure has been gaining in popularity compared with the suturing technique.

Various modified techniques have been reported, including fibrin glue–assisted,2 forceps-guided,1–8 sleeve-guided,15 and needle-guided4,13 techniques. However, challenges remain, although these modifications have improved the surgical time, postoperative temporal hypotony,1,2,4 and visual outcomes.13 A current problem is the difficulty of leading the IOL haptics from the posterior chamber to outside the eye through the sclerotomy. Most techniques require use of a forceps, which is introduced into the posterior chamber through a sclerotomy to grasp the IOL haptic and draw it out. In addition to the difficulty of grasping the haptic tip, especially the tip of the second haptic, the forceps-guided technique has several problems, i.e., ciliary body detachment with introduction of the forceps through the sclerotomy, breaking or bending of the haptic when it is pulled out, and leakage of intraocular fluid from the wound, which requires suturing.1–8 Although the double-needle technique reported by Yamane et al13 and the lock-and-lead technique reported by Akimoto et al15 made the procedure easier and reduced the risks of complications, the difficulty level of this surgical technique remains high because it requires controlling the position of the IOL in the eye while grasping the haptic with a forceps or introducing the haptic tip into a thin needle. Furthermore, greater-than-normal stress on the wound from the forceps used to grasp the haptic, especially the second one, induces tissue damage. Therefore, an easier and less-invasive technique of scleral fixation of the posterior chamber IOL is needed, especially when drawing out the haptics from the posterior chamber through the sclerotomy.

We developed a novel technique in which an extremely thin silicone tube is introduced into the posterior chamber through the corneoscleral wound and drawn out through a sclerotomy, and the other end of the tube then is connected to the tip of the IOL haptic outside the eye. Afterward, the haptics are drawn out of the eye from the posterior chamber by simply drawing the tube through the sclerotomy after inserting the IOL connected to the tube. This technique is easier because most maneuvers are performed outside the eye and less invasive because the silicone microtube is thin, thread-like, and soft.

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Methods

In this retrospective case series report, the charts of patients who underwent silicone microtube–assisted scleral fixation of a posterior chamber IOL were reviewed. The surgical outcomes including the IOL position, visual acuity, refractive error, and intraoperative and postoperative complications were analyzed.

The Institutional Review Committee of Aichi Medical University approved the study protocol. All clinical procedures were conducted according to the principles of the Declaration of Helsinki. All patients provided informed consent after the study protocol, the procedure, and its possible complications were explained.

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Surgical Procedures

A video (see Video, Supplemental Digital Content 1, http://links.lww.com/IAE/A839) shows the procedures used in this technique.

All surgeries were performed under local anesthesia induced by a sub-Tenon injection of 3 mL of 2% xylocaine. A radial, half-thickness scleral incision approximately 1-mm long was created 1.7 mm from the limbus at the planned site to lead the haptic from the posterior chamber after a conjunctival incision (Figure 1). A second radial scleral incision then was made in the same manner in parallel with and approximately 1.5 mm counterclockwise away from the first incision. A scleral tunnel was made between these 2 scleral incisions using a 27-gauge blade. Finally, a scleral pocket approximately 0.5-mm long was created counterclockwise to the second radial incision as an extension of the first scleral tunnel for later insertion of the haptic tip. The same scleral incisions, tunnel, and pocket were made in a same manner 180° on the opposite side.

Fig. 1

Fig. 1

A 27-gauge infusion cannula was placed 3.5 mm posterior to the limbus away from the scleral incisions. Two additional ports were placed and a vitrectomy was performed if necessary in eyes that had not undergone a previous vitrectomy. A 2.8-mm long sclerocorneal incision was made superiorly for later IOL insertion (Figure 1). In cases of IOL dislocation, the dislocated IOL was extruded through the sclerocorneal incision.

A 30-gauge thin-wall needle (TSK Ultra-Thin Wall Needle, Tochigi Seiko, Tochigi, Japan) was inserted diagonally into the posterior chamber from the first scleral incision bed 1.7 mm from the limbus (Figure 2). A straight 9 to 0 polypropylene needle was bent, inserted into the anterior chamber through the sclerocorneal incision, connected to the 30-gauge needle (Figure 3), and drawn out through the sclerotomy by pulling out the 30-gauge needle from the first scleral incision. At this point, a 9 to 0 polypropylene filament passes through the eye from the sclerocorneal incision through the anterior/posterior chamber and sclerotomy to the first scleral incision (Figure 4). The end of the 9 to 0 polypropylene filament protruding from the sclerocorneal incision was ligated to the end of a silicone microtube (no. 244-1175-01, Hagitec Co, Ltd, Chiba, Japan) approximately 10-cm long, and the end of the silicone microtube protruding from the ligation was trimmed (Figure 5). The silicone microtube was passed through the eye through the sclerocorneal incision, the anterior/posterior chamber, and the sclerotomy to the outside of the first scleral incision by slowly pulling out the 9 to 0 polypropylene filament, indicating that these procedures were performed in an ab-interno manner (Figure 6). Finally, the silicone microtube was introduced through the scleral tunnel attached to the 9 to 0 polypropylene (Figure 7). The same procedures were performed 180° away on the opposite side (Figure 8).

Fig. 2

Fig. 2

Fig. 3

Fig. 3

Fig. 4

Fig. 4

Fig. 5

Fig. 5

Fig. 6

Fig. 6

Fig. 7

Fig. 7

Fig. 8

Fig. 8

The other end of the silicone microtube was passed through an IOL injection cassette and connected to the IOL haptic by inserting the haptic tip into the tube (or covering the haptic with the tube) (Figure 9). A foldable, three-piece acrylic IOL (NX70, Santen Pharmaceutical Co. Ltd. Osaka, Japan) (7.0-mm diameter optic, 13.2-mm long) was used. The overlap between the haptic and the silicone microtube was as short as approximately 1 mm. Using an injector, the foldable IOL was inserted into the anterior chamber through the 2.8-mm sclerocorneal incision. The antecedent haptic in the anterior/posterior chamber was connected to the silicone microtube, whereas the trailing haptic was outside the sclerocorneal incision. The trailing haptic was connected to the end of the other silicone microtube in the same manner and inserted into the anterior/posterior chamber with IOL forceps (Figure 10). Each haptic was pulled from the posterior chamber through the sclerotomy to the outside of the first scleral incision by slowly pulling out each silicone microtube and finally passed through the scleral tunnel by leading with the silicone microtube, which had previously been passed through the scleral tunnel (Figure 11). Finally, each haptic tip was disconnected from the silicone microtube and inserted into the scleral pocket (Figure 12).

Fig. 9

Fig. 9

Fig. 10

Fig. 10

Fig. 11

Fig. 11

Fig. 12

Fig. 12

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Results

Two surgeons (M.K. and T.K.) performed the silicone microtube–assisted scleral fixation of a posterior chamber IOL in six eyes of six patients. The patient characteristics are shown in Table 1. The mean patient age at the time of surgery was 65.2 ± 16.8 years (range, 41–88 years). Two eyes were aphakic, one had a dislocated posterior chamber IOL in the vitreous cavity, two had subluxated crystalline lenses, and one had IOL whitening and glistenings. The mean follow-up time was 3.3 ± 2.7 months (range, 1–8 months).

Table 1

Table 1

Standard ophthalmologic examinations were performed, i.e., measurements of the best-corrected visual acuity and intraocular pressure, slit-lamp examination, and indirect fundus examination preoperatively and postoperatively. The mean preoperative best-corrected visual acuity was 0.96 logarithm of the minimum angle of resolution (20/182) that improved to 0.62 logarithm of the minimum angle of resolution (20/43) at 1 month. The mean postoperative refraction was -0.06 ± 0.4 diopter, which did not differ markedly (P = 0.53) from the predicted value. Postoperative hypotony and intraocular pressure elevations were defined, respectively, as intraocular pressures below 6 mmHg and higher than 25 mmHg.

One intraoperative complication occurred in which the silicone microtube broke during withdrawal in one (16.7%) eye, and the haptic was drawn through with a 25-gauge forceps.

The average surgical time of the six cases was 158 minutes (range, 133–205 minutes). The average time spent solely on this procedure was 99 minutes (range, 78–137 minutes).

The postoperative complications included transient ocular hypotension in one (16.7%) eye, vitreous hemorrhage in two (33.3%) eyes, and choroidal detachment in one (16.7%) eye, all of which resolved without treatment in a few days. One eye that underwent a simultaneous trabeculotomy presented with hypotension and a vitreous hemorrhage, and it was difficult to know which surgery was responsible. No other severe complications such as retinal detachment, endophthalmitis, or IOL dislocation occurred during the follow-up period.

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Discussion

The benefit of this novel technique of IOL scleral fixation is minimal or no intraocular IOL manipulation, the most difficult part of this surgery, resulting in greater ease and safety. The only intraocular manipulation required is insertion of the IOL into the chamber, which represents the same or fewer procedures as during an uncomplicated IOL implantation in a treatment-naïve cataract case.

Any previous methods, such as the forceps-guided, sleeve-guided, or needle-guided techniques,1–15 require at least holding the haptic with forceps in the chamber, which requires a clear cornea, a well-dilated pupil, and a certain level of surgical skill. Using the current technique, an IOL was implanted smoothly in an eye with only 4 mm of pupillary dilation. Furthermore, manipulating forceps through a corneal side port exerts stress on the cornea, especially when gasping and manipulating the second haptic.4,13,15

The current technique reduced the difficulty of drawing out the haptics from the posterior chamber to the outside of the eye through the sclera. Pulling the silicone microtube through the sclerotomy site facilitated easy and simple haptic manipulation once the IOL that was connected to the silicone microtube was inserted into the chamber. The silicone microtube is very thin and sufficiently soft and, therefore, is less invasive to the eye, and there is less stress on the IOL and the haptics. Thus, this technique reduces the risk of haptic breakage or ocular tissue damage.

Hypotony and bleeding related to existing scleral fixation surgeries were postoperative complications that might occur due to ciliary detachment or wound leakage. Inserting or manipulating vitreous forceps or specially designed 25- or 27-gauge forceps through a diagonally constructed sclerotomy, in contrast to a perpendicular sclerotomy, without a trocar poses some risk of ciliary detachment.1–8 In addition, because the diameters of the 25- or 27-gauge instruments are larger than that of the haptics, the vitreous fluid might leak after vitreous shaving if the sclerotomy site is not well sutured.1 The current technique using a silicone microtube with a 0.2-mm external diameter, which is only 0.05 mm wider than the haptic diameter, reduced the possible risks of ciliary detachment and leakage as well as the double-needle technique in which a 30-gauge sharp needle is used.13 The risk of ciliary detachment also was reduced by introducing the silicone microtube from the posterior chamber to the sclera through a 9 to 0 polypropylene thread, in an ab-interno manner.

The hypotony and choroidal detachment occurred in the same patient. A capsular rupture during a previous cataract surgery resulted in dislocation and phacolysis. Fortunately, no leak was observed after our surgery, and therefore, we could not determine whether the procedure under discussion or the original inflammation caused the postoperative hypotony and choroidal detachment. We will address these complications in subsequent studies and consider suturing of the scleral slit if the complications are frequent occurrences. Regarding the two cases of vitreous hemorrhage, one seemed to result from administration of oral warfarin, and the other cause was unknown.

This technique also has the additional following advantages. The risk of the IOL dropping into the vitreous cavity is eliminated when it is inserted into the chamber because the haptics are already connected to the tubes; fewer special skills are required because the procedures are similar to the IOL-suturing technique with which many surgeons are familiar; a scleral flap and suture are not required because the haptics are introduced easily into the sclerotomy and scleral tunnel through the silicone microtube; and the procedure is cost effective because the silicone microtubes costs only approximately $1.50/surgery.

However, improvements are needed in the insertion of the haptics into the silicone microtube, which requires fine forceps manipulations, although this step is performed outside the eye. Because the diameter of a haptic of a typical three-piece IOL is approximately 0.15 mm and the inner diameter of the silicone microtube is 0.1 mm, the tube should be expanded slightly; this is challenging because the tube is very thin and difficult to handle. One intraoperative complication that we experienced in an eye in the current series was tube breakage, possibly due to a minute tear that developed during the connection of the tube to the haptic. A special tool to facilitate this should be developed. We currently pinch a haptic and a microtube 0.5 mm from the end with suturing forceps (Geuder, Heidelberg, Germany) in each hand, insert only the haptic tip, and stroke the tube toward the haptic root. Only a 1-mm cover provided sufficient adhesion, and the tube did not detach from the haptic when drawn out through the sclerotomy if it was made with a 30-gauge needle or a thicker needle or blade. Unlinking of the tube and haptic occurred when the sclerotomy was made with a 9 to 0 polypropylene straight needle and not with a 30-gauge needle.

However, our procedure required more time compared with previously reported methods. We believe that the time required to perform the procedure will become shorter as the number of cases increases because this procedure is still in the initial exploratory trial-and-error stage. We should evaluate the surgical time again in the future when the surgeons become more adept at performing it.

This novel technique of silicone microtube–assisted scleral fixation of a posterior chamber IOL is easier and safer than the previous methods for implanting an IOL in cases with IOL dislocation, crystalline lens subluxation, or aphakic eyes without an adequate residual lens capsule. A novice surgeon can perform this technique because it does not require IOL manipulation intraocularly. A longer follow-up analysis of more cases is required to confirm the anatomical and functional advantages of this technique.

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References

1. Gabor SGB, Pavlidis MM. Sutureless intrascleral posterior chamber intraocular lens fixation. J Cataract Refract Surg 2007;33:1851–1854.
2. Agarwal A, Kumar DA, Jacob S, et al. Fibrin glue-assisted sutureless posterior chamber intraocular lens implantation in eyes with deficient posterior capsules. J Cataract Refract Surg 2008;34:1433–1438.
3. Agarwal A, Jacob S, Kumar DA, et al. Handshake technique for glued intrascleral haptic fixation of a posterior chamber intraocular lens. J Cataract Refract Surg 2013;39:317–322.
4. Rodríguez-Agirretxe I, Acera-Osa A, Ubeda-Erviti M. Needle-guided intrascleral fixation of posterior chamber intraocular lens for aphakia correction. J Cataract Refract Surg 2009;35:2051–2053.
5. Saleh M, Heitz A, Bourcier T, et al. Sutureless intrascleral intraocular lens implantation after ocular trauma. J Cataract Refract Surg 2013;39:81–86.
6. Kumar DA, Agarwal A, Prakash G, et al. Glued posterior chamber IOL in eyes with deficient capsular support: a retrospective analysis of 1-year post-operative outcomes. Eye 2010;24:1143–1148.
7. Kumar DA, Agarwal A, Prakash D, et al. Glued intrascleral fixation of posterior chamber intra- ocular lens in children. Am J Ophthalmol 2012;153:594–601.
8. Totan Y, Karadag R. Trocar-assisted sutureless intrascleral posterior chamber foldable intra-ocular lens fixation. Eye 2012;26:788–791.
9. Scharioth GB, Prasad S, Georgalas I, et al. Intermediate results of sutureless intrascleral posterior chamber intraocular lens fixation. J Cataract Refract Surg 2010;36:254–259.
10. Kumar DA, Agarwal A, Packiyalakshmi S, et al. Complications and visual outcomes after glued foldable intraocular lens implantation in eyes with inadequate capsules. J Cataract Refract Surg 2013;39:1211–1218.
11. Narang P. Modified method of haptic externalization of posterior chamber intraocular lens in fibrin glue-assisted intrascleral fixation: no-assistant technique. J Cataract Refract Surg 2013;39:4–7.
12. Beiko G, Steinert R. Modification of externalized haptic support of glued intraocular lens technique. J Cataract Refract Surg 2013;39:323–325.
13. Yamane S, Inoue M, Arakawa A, Kadonosono K. Sutureless 27-gauge needle-guided intrascleral intraocular lens implantation with lamellar scleral dissection. Ophthalmology 2014;121:61–66.
14. Ohta T, Toshida H, Murakami A. Simplified and safe method of sutureless intrascleral posterior chamber intraocular lens fixation: Y-fixation technique. J Cataract Refract Surg 2014;40:2–7.
15. Akimoto M, Takayama K, Nakagawa S, Hiroi K. Intrascleral fixation technique using catheter needles and 30-gauge ultrathin needles: lock-and-lead technique. J Cataract Refract Surg 2014;41:257–261.
Keywords:

posterior chamber intraocular lens; scleral fixation; silicone microtube

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