Transscleral suture fixation is one of the important surgical techniques used in various situations, including the transscleral fixation of a posterior chamber intraocular lens (IOL) or artificial iris prostheses, fixation of a capsular tension ring or segment, and repositioning of dislocated in-the-bag or out-of-the-bag IOLs.1–8 In the most common scleral suture fixation techniques, the suture is tied on the scleral bed beneath a scleral flap or in a scleral groove or pocket. The creations of large conjunctival openings and scleral flaps, grooves, or pockets are traumatic, resulting in scarring of conjunctiva and sclera, and may therefore be disadvantageous to potential future surgical procedures. In some cases with previously performed surgeries or ocular trauma, scarring of the conjunctiva–scleral tissue may add to the difficulty of performing the conjunctival dissections and the scleral flaps. The technique can also lead to late complications, including dislocation of the IOL induced by dehiscence of scleral tissue because of the cutting effect of the tying sutures, leading to loss of the scleral support, and erosions of the stiff cutting ends of the suture, increasing the risk of endophthalmitis.9–11 Symmetric and balanced tensions of the fixation sutures are crucial for the well-centered IOL position. The suture tension must be adjusted in the procedure during fastening to the sclera in the conventional suturing technique. Once the suture is tied on the sclera, the tension is not adjustable for optimized position of the implants. We describe an adjustable and less traumatic suturing technique for transscleral fixation by using the principle of a buckle-slide device. A typical buckle-slide device is composed of a frame with a bar in its middle and a chape. It is widely used as a fastener and adjuster for straps or belts in daily life (see Figure, Supplemental Digital Content 1, http://links.lww.com/IAE/A858). The friction between the strap (or belt) and the buckle-slide provides adequate force for fastening. The present suturing technique using the mechanism of the device requires neither large conjunctival dissections nor the manipulations on the sclera (flaps, grooves, or pockets). The technique is safe and reliable in firmly fixating the suture within the sclera.
Institutional review board approval was obtained from Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China, for this prospective, noncomparative, interventional case series. The study adhered to the principles of the Declaration of Helsinki. All participants treated by this technique provided written informed consent of possible benefits and risks. All patients underwent comprehensive preoperative and postoperative ophthalmic examinations, and data were collected prospectively, including age, sex, best-corrected visual acuity, refractive error, intraocular pressure, and postoperative measurements of IOL position by using a Scheimpflug camera (Pentacam, Oculus Optikgeräte GmbH, Wetzlar, Germany).
Surgeries were performed by one of the authors (J.H.). We use the four-point transscleral fixation of an Akreos AO60 (Bausch & Lomb, North Clearwater, FL) foldable posterior chamber IOL, for example, to demonstrate the mechanism and surgical procedures of the technique. The supplemental video demonstrates the procedures (see Video, Supplement Digital Content 2, http://links.lww.com/IAE/A859). An 8-0 polypropylene thread (Prolene, Polypropylene Suture; Ethicon, Johnson-Johnson, New Brunswick, NJ) with a curved needle was bisected. One half (the fixation thread) was used to fix the posterior chamber IOL. The other half (the buckle-slide thread) was used to create the buckle-slide structure to fixate the fixation thread. The procedures of introducing the fixation thread into the eye and looping the eyelets of the IOL were similar to the previously published methods.12.13 Suture-in-needle technique to introduce the fixation thread into the eye was performed. The free end of the 8-0 polypropylene thread was threaded approximately 3 mm into the tip of a 27-gauge needle. The suture was draped away from the cutting portion of the needle. A direct ab externo puncture of the needle was performed at the fixation site to introduce the loop of the suture into the eye, leaving the other end of thread exterior to the eye. The loop of the suture was then grasped by forceps introduced through the main incision. The end of the suture in the needle was taken out from the main incision by forceps using the manipulations similar to the handshake technique.14 The 27-gauge needle was withdrawn from the eye. The suture was then looped through both eyelets on the IOL haptics on the nasal side. An ab externo puncture of the same 27-gauge needle was performed at the second fixation point and was guided out from the main incision by forceps. The end of the polypropylene thread was threaded into the lumen of the needle. After withdrawing the needle, the end of the suture was externalized from the second fixation point. The same procedures were repeated to loop the haptics and introduce and externalize the ends of the thread on the temporal side. For eyes with scarring of conjunctiva–Tenon capsule due to previous surgery or thin conjunctiva–Tenon capsule, a direct ab externo picturing without conjunctival openings was performed using the 27-gauge needle. For eyes with thickened conjunctiva–Tenon capsule, the puncturing was performed after creation of minimal conjunctival openings at the scleral fixation sites. For a two-point fixation, the similar technique to introduce the thread into the eye and to pass it out of the main incision was performed. The suture threads were secured to the IOL haptics by knots. After folding and implanting the IOL into the posterior chamber, the buckle-slide suturing technique was performed for each externalized thread for fixation. The buckle-slide thread was tied around one of the externalized fixation threads, creating a knot and a loop around the fixation thread. The needle of the buckle-slide thread was then started with an intrascleral pass from the sclerotomy to the adjacent transscleral penetration site parallel to the limbus. The needle was then pulled out transconjunctivally by a needle holder. The thread was further pulled to lead the knot and the fixation thread entering the scleral tunnel, leaving the externalized end of the fixation thread outside the sclerotomy. A distinct increase in friction could be felt when the structure entered the scleral tunnel. The loop tied on the fixation thread and the walls of the scleral tunnel together work as a buckle-slide structure to secure the fixation thread. The loop works as the bar of the buckle slide. The scleral walls work as the buckle frame. The knot works as the chape to anchor the buckle-slide structure in the sclera. The friction of the fixation thread is generated by the buckle-slide structure and does not rely on the length of the suture buried in the sclera. The principles of the buckle-slide device and buckle-slide suture are demonstrated in Figures 1 and 2. After repeating the same maneuvers to fixate the other externalized fixation threads, the tensions of the fixation threads to center the IOL were adjusted in a bimanual manner. One instrument (forceps or needle holder) was used to hold the externalized buckle-slide thread to stabilize the eye and to counteract the friction generated by the buckle-slide structure, and the other instrument was used to pull the externalized fixation thread in the opposite direction to adjust the suture tension. A distinct friction generated by the buckle-slide suture could be felt in this procedure. After checking the IOL stability by pressing the optics using a Sinskey hook or vitreous cutter, the externalized ends of all the threads were cut flush to the conjunctival surface. The small conjunctival openings were left sutureless. For a two-point fixation of a posterior chamber IOL or sutured capsular tension ring or segment, the same technique is used to fixate and adjust the scleral fixation sutures (Figure 3).
A total of 12 patients (7 men and 5 women) were included. The mean age was 56 years (±SD, 18.6; range, 19–73 years). The indications for surgery included aphakia after pars plana vitrectomy secondary to traumatic injury with retinal detachment repair (n = 5), traumatically dislocated crystalline lens (n = 2), dislocated crystalline lens due to Marfan syndrome (n = 2), posteriorly dislocated posterior chamber IOL after phacovitrectomy (n = 2), and posteriorly dislocated posterior chamber IOL after cataract surgery (n = 1). Different surgical approaches combined with transscleral fixation were performed. For vitrectomized eyes after pars plana vitrectomy secondary to traumatic injury, transscleral IOL fixation under continuous anterior chamber infusion was performed (n = 5). For eyes with posteriorly dislocated posterior chamber IOL after cataract surgery or phacovitrectomy, or eyes with traumatically dislocated crystalline lens, combined pars plana vitrectomy and transscleral IOL fixation was performed (n = 5). For dislocated crystalline lens due to Marfan syndrome, combined lensectomy, anterior vitrectomy, and transscleral IOL fixation was performed (n = 2). The types of transscleral-fixated IOLs included four-point fixation of Akreos AO60 (Bausch & Lomb) IOL (n = 8), two-point fixation of C-flex 620H (Rayner) IOL (n = 2), and two-point fixation of ar40e (AMO) IOL (n = 2). For eyes with posteriorly dislocated IOL (two ar40e IOLs and one C-flex 620H IOL), the dislocated IOLs were transsclerally fixated using the present technique. For aphakia and eyes with dislocated lenses, the Akreos AO60 IOL (n = 8) and C-flex 620H IOL (n = 1) were used. The mean follow-up period was 9.3 ± 8.5 months (range 3–16 months). Preoperative logarithm of the minimum angle of resolution visual acuity was logMAR 0.80 ± 0.72 (Snellen 20/126). Logarithm of the minimum angle of resolution visual acuity at the final follow-up was logMAR 0.29 ± 0.42 (Snellen 20/39). No intraoperative complications were observed. Postoperative complications included transient vitreous hemorrhage in one eye, which was quickly absorbed without medical intervention, and transient hypertension in one eye, which was managed by topical antiglaucomatic agents. No suture erosion, suture loosening, hypotony, scleral atrophy, chronic inflammation, or retinal tear and/or detachment were observed in any of the patients. The IOLs were well centered within the follow-up period.
Although various innovative techniques have been developed for IOL fixation in patients with insufficient capsular support, the surgical management remains challenging. Most techniques involve large conjunctival openings, scleral flaps, groves, or pockets to prevent exposure of the suture knot. Surgical trauma of scleral suture fixation is reduced by two flapless techniques, the Z-suture and the friction knot techniques.15,16 Both techniques use friction to secure the transscleral suture. The friction of the Z-suture originates from the zigzag intrascleral path. The technique requires a wide conjunctival opening to expose the sclera for zigzagging the intrascleral suture. The friction knot technique stabilizes the suture by burying a lumpy knot in the needle track instead of zigzagging the thread in the sclera and does not require a wide conjunctival dissection. The tension of the fixation suture relies on the position of the knot incarcerated in the sclera. Once the knot enters the scleral tunnel, it is difficult to adjust the position of the intrasclerally fixated knot and the tension of the suture because of the distinct frictional force.
The buckle-slide suture shares the simplicity of flapless techniques (friction knot technique and the Z-suture technique); however, the working mechanism is different (Figure 1). There are several reasons for the reliable fixation of this technique. First, the 8-0 polypropylene thread can create a bigger knot and higher friction to chape the structure in the sclera. In some cases, leading the knot of the 8-0 thread into the sclera was difficult because of its big size. To solve the problem, we have made a small modification for the technique. Before performing the intrascleral pass of the curved needle or before further pulling the thread to incarcerate the knot, a wedge-shaped scleral tunnel of about 3 mm in length was made by the tip of a 27-gauge needle. The knot could be led and incarcerated into the tunnel smoothly after this modification. The 8-0 polypropylene thread also has a higher tensile strength and stability than the conventional 10-0 thread. An immediate, distinct friction could be felt in the procedure of adjusting the suture tension. This friction should be counteracted using a bimanual technique to stabilize the eye, indicating that the technique is safe and reliable in firmly fixing the suture within the sclera. Second, the immediate stabilization of the sutured IOL was intraoperatively confirmed by pressing the IOL optics using an instrument. No intraoperative loosening of the suture was observed. Third, the healing of sclera could further increase the late fixation. No evidence of suture loosening and IOL dislocation were observed in any of our cases within the postoperative follow-up period.
The present technique has several advantages. First, it shares the benefits of a buckle-slide structure, which is one of the widely used devices working as an adjuster and fastener in securing a range of items (various straps or belts) in daily life. In providing adequate friction for reliable scleral fixation, the structure provides convenient adjustability as well, which is its major advantage over the other fixation methods. Second, this technique decreases the risk of scleral dehiscence, late dislocation, and erosion of the stiff cutting end of the suture compared with the flap techniques. Third, the technique is less traumatic because of minimal conjunctival openings and fewer manipulations on the sclera. Minimal conjunctival dissection is a particular strength of this method and is especially appropriate for patients with glaucoma and in those with potential for incisional glaucoma surgery. Fourth, it has a universal applicability for the suture fixation of various implants, including different types of IOLs, capsular tension rings or segments, artificial iris prostheses, and IOL–capsular-bag complexes. Moreover, the method can be used, regardless of the suturing technique (ab externo or ab interno), the suture design (straight or curved needle), and the suture material (polypropylene or polytetrafluoroethylene).
There are limitations of the present technique. First, the method seems to be potentially complicated and time-consuming, especially in a four-point fixation, because of the repeated manipulations of creating the buckle-slide suturing. However, the technique reduces the manipulations on the conjunctiva and sclera (i.e., flaps, pockets, or grooves) in conventional transscleral fixation techniques and thus shortens surgical time and does not compromise simplicity. A four-point IOL fixation using the present technique prevents tilt and pupil capture of the IOL. The technique might be more complicated than the intrascleral fixation technique performed with the aid of small-gauge needles that also avoid large dissections of the conjunctiva and manipulations on the sclera; however, intrascleral fixation of a three-piece IOL has the limitations of relatively high incidences of pupil capture and IOL tilt.17 Moreover, most of the three-piece IOLs are hydrophobic, which might have higher potential risk of pigmental dispersion. Second, there is concern about the potential inconvenience in the manipulation because of many suture ends exposed after the buckle-slide suturing. Nevertheless, the exposure of the suture ends is at the final steps of the surgery, and the suture ends can be trimmed immediately after adjusting the tensions, without hindering surgical manipulations.
In summary, the present technique is an alternative, flapless method for the transscleral fixation of IOLs. It provides both reliable suture stability and convenient adjustability to optimize the position of the IOLs. A study with a longer follow-up time and more cases is required to confirm the long-term stability of this method and compare it with other methods of fixation.
1. Smiddy WE, Sawusch MR, O'Brien TP, et al. Implantation of scleral-fixated posterior chamber intraocular lenses. J Cataract Refract Surg 1990;16:691–696.
2. Lewis JS. Ab externo sulcus fixation. Ophthalmic Surg 1991;22:692–695.
3. Lewis JS. Sulcus fixation without flaps. Ophthalmology 1993;100:1346–1350.
4. Smiddy WE. Modification of scleral suture fixation technique for dislocated posterior chamber intraocular lens
implants. Arch Ophthalmol 1998;116:967.
5. Hoffman RS, Fine IH, Packer M. Scleral fixation without conjunctival dissection. J Cataract Refract Surg 2006;32:1907–1912.
6. Gimbel HV, Condon GP, Kohnen T, et al. Late in-the-bag intraocular lens
dislocation: incidence, prevention, and management. J Cataract Refract Surg 2005;31:2193–2204.
7. Gimbel HV, Brucks M, Dardzhikova AA, Camoriano GD. Scleral fixation of a subluxated intraocular lens
-capsular bag complex through a fibrotic continuous curvilinear capsulorhexis. J Cataract Refract Surg 2011;37:629–632.
8. Spitzer MS, Yoeruek E, Leitritz MA, et al. A new technique for treating posttraumatic aniridia with aphakia: first results of haptic fixation of a foldable intraocular lens
on a foldable and custom-tailored iris prosthesis. Arch Ophthalmol 2012;130:771–775.
9. Solomon K, Gussler JR, Gussler C, Van Meter WS. Incidence and management of complications of transsclerally sutured posterior chamber lenses. J Cataract Refract Surg 1993;19:488–493.
10. McAllister AS, Hirst LW. Visual outcomes and complications of scleral-fixated posterior chamber intraocular lenses. J Cataract Refract Surg 2011;37:1263–1269.
11. Sindal MD, Nakhwa CP, Sengupta S. Comparison of sutured versus sutureless scleral-fixated intraocular lenses. J Cataract Refract Surg 2016;42:27–34.
12. Terveen DC, Fram NR, Ayres B, Berdahl JP. Small-incision 4-point scleral suture fixation of a foldable hydrophilic acrylic intraocular lens
in the absence of capsule support. J Cataract Refract Surg 2016;42:211–216.
13. Peden M, Adams S, Huffman B, Kaushal S. Alternative technique for implantation of a scleral-fixated intraocular lens
. J Cataract Refract Surg 2009;35:226–229.
14. 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.
15. Szurman P, Petermeier K, Aisenbrey S, et al. Z-suture: a new knotless technique for transscleral suture fixation of intraocular implants. Br J Ophthalmol 2010;94:167–169.
16. Oskala P. Friction knot to fixate scleral sutures. J Cataract Refract Surg 2015;41:497–500.
17. Yamane S, Sato S, Maruyama-Inoue M, Kadonosono K. Flanged intrascleral intraocular lens
fixation with double-needle technique. Ophthalmology 2017;124:1136–1142.