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OCULAR SURGERY NEWS EUROPE/ASIA-PACIFIC EDITION March 2008

Posterior chamber IOL can be fixated with fibrin glue

A new technique that relies on glue to implant IOLs in eyes that lack posterior capsular support is described.

We have devised a new surgical technique for implantation of a posterior chamber IOL with the use of biological glue in eyes with deficient or absent posterior capsules. We used a quick-acting surgical fibrin sealant derived from human blood plasma, with both hemostatic and adhesive properties.

Scleral-fixated IOL

IOL implantation in eyes that lack posterior capsular support has been accomplished in the past by using iris-fixated IOL, anterior chamber IOL and transscleral IOL fixation through the ciliary sulcus or pars plana. Surgical expertise, prolonged surgical time, suture-induced inflammation, suture degradation, and delayed IOL subluxation or dislocation due to broken suture are some of the limitations in sutured scleral-fixated IOL. It is also difficult and time-consuming, requiring minute and perfect adjustment of suture length and tension to ensure good centration of the scleral-fixated IOL.

Fibrin glue

Fibrin glue has been used previously in various medical specialties as a hemostatic agent to arrest bleeding, seal tissues and as an adjunct to wound healing. The fibrin kit we used was ReliSeal (Reliance Life Sciences). It is available in a sealed pack that contains freeze-dried human fibrinogen (20 mg/0.5 mL), freeze-dried human thrombin (250 IU/0.5 mL), aprotinin solution (1,500 KIU in 0.5 mL), one ampoule of sterile water, four 21-gauge needles, two 20-gauge blunt application needles, and an applicator with two mixing chambers and one plunger guide.

Scleral flaps prepared 180° diagonally apart. Note the infusion cannula fixed in an eye without any capsule.	Tip of the haptic grabbed by the 25-gauge micro-rhexis forceps and then externalized under the scleral flap.	Superior haptic grabbed by the 25-gauge micro-rhexis forceps and then externalized under the scleral flap.
Fibrin glue applied. Note the haptic, which is externalized.	Posterior chamber IOL well-positioned and centered.	Images: Agarwal A

Surgical technique

After inserting the infusion cannula or anterior chamber maintainer, localized peritomy is done. Two partial-thickness limbal-based scleral flaps about 3 mm by 3 mm are created exactly 180° diagonally apart (Figure 1) and about 1.5 mm from the limbus. This is followed by vitrectomy via pars plana or anterior route to remove all vitreous traction. Two straight sclerotomies with a 22-gauge needle are made under the scleral flaps created. The sclerotomies are positioned in such a way that the superior one lies close to the upper edge of the flap and the inferior one lies close to the lower edge of the flap. The flaps are positioned in the superior-nasal and inferotemporal quadrants.

A scleral tunnel incision is then prepared for introducing the IOL. While the IOL is being introduced with one hand of the surgeon using McPherson forceps, end-gripping 25-gauge micro-rhexis forceps (MicroSurgical Technology) are passed through the inferior sclerotomy using the other hand.

The tip of the leading haptic is then grasped with the micro-rhexis forceps, pulled through the inferior sclerotomy following the curve of the haptic (Figure 2) and externalized under the inferior scleral flap. Similarly, the trailing haptic is also externalized through the superior sclerotomy under the scleral flap (Figure 3). Then, the reconstituted fibrin glue thus prepared is injected through the cannula of the double syringe delivery system under the superior (Figure 4) and inferior scleral flaps. Local pressure is applied on the flaps for about 10 to 20 seconds for the formation of fibrin polypeptides (Figure 5). The anterior chamber maintainer or the infusion cannula is removed. The conjunctiva is also closed with the same fibrin glue.

In cases in which patients had a luxated IOL, similar lamellar scleral flaps as described earlier are created, and the luxated IOL haptic is then grasped with the 25-gauge rhexis forceps and exteriorized and glued under the scleral flaps (Figures 6a to 6e). The haptic of the IOL, if protruding beyond the scleral flap, can be tucked in a tunnel created in the sclera (Figure 7). Our follow-up anterior segment OCT showed postoperative perfect scleral flap adhesion as early as day 1 and continued to remain well maintained at 1 week and 2 months.

Discussion

This fibrin glue-assisted sutureless posterior chamber IOL implantation technique would be useful in many clinical situations in which scleral-fixated IOLs are indicated, such as luxated IOL, dislocated IOL, zonulopathy or secondary IOL implantation. In a case with a dislocated posterior chamber PMMA IOL, the same IOL can be repositioned, thereby reducing the need for further manipulation. Externalization of the greater part of the haptics along the curvature stabilizes the axial positioning of the IOL and thereby prevents any IOL tilt. In the 12 eyes of our 12 patients, no complications such as postoperative inflammation, hyphema, decentration, glaucoma or corneal edema have been seen after a regular follow-up.

We expect less incidence of uveitis-glaucoma-hyphema syndrome in fibrin glue-assisted IOL implantation as compared with sutured scleral-fixated IOL implantation. In the former, the IOL is well stabilized and stuck onto the scleral bed and thereby has decreased intraocular mobility; in the latter, there is increased possibility of IOL movement or persistent rub over the ciliary body. Visually significant complications due to late subluxation, which has been known to occur in sutured scleral-fixated IOLs, may also be prevented as sutures are avoided in this technique. Moreover, the frequent complications of secondary IOL implantation, such as secondary glaucoma, cystoid macular edema or bullous keratopathy, were not seen in any of our patients. Another important advantage of this technique is the prevention of suture-related complications such as suture erosion, suture knot exposure, or dislocation of IOL after suture disintegration or broken suture.

The other advantages of this technique are the rapidity and ease of surgery. The technique eliminates tying the difficult-to-handle 10-0 Prolene suture to the IOL haptic eyelets, the time required to ensure good centration before tying down the knots, and the time required for suturing scleral flaps and closing the conjunctiva, so the total surgical time is significantly reduced. It is also easier and does not require much surgical expertise to use the 25-gauge forceps to grasp and exteriorize the haptic. Fibrin glue takes only 20 seconds to act in the scleral bed, and it helps in adhesion and hemostasis. Fibrin glue has been shown to provide airtight closure, and by the time the fibrin starts degrading, surgical adhesions would have already occurred in the scleral bed.

The commercially available fibrin glue that we used is virus inactivated and is checked for viral antigen with polymerase chain reaction; hence, the chance of transmission of infection is low. But with tissue derivatives, there is always a theoretical possibility of transmission of viral infections; therefore, it is mandatory to get informed consent from the patient before the procedure. Although the use of fibrin glue in ophthalmology is considered off-label, it has been successfully used in the eye. Its various uses in the eye include repair of lacerated canaliculi to seal full thickness macular holes, cataract incisions, corneal perforations and traumatic lens capsule perforations. It has also been used for temporary closure of scleral flaps after trabeculectomy in eyes with hypotony, conjunctival fistula closure, conjunctival autografts and amniotic membrane transplantation.

Gabor et al have shown sutureless scleral IOL fixation by placing the IOL haptic in a scleral tunnel. Our technique differs from other sutureless methods by use of the fibrin glue, which enhances the rate of adhesion with hemostasis. We also used scleral flaps as in conventional-sutured scleral-fixated IOLs, and this makes the learning curve simple. There is also no danger of intraocular infection gaining entry through the tunnel, as the fibrin glue hermetically seals the flaps, leaving behind no possible entry route for microbes. There was no glue-induced intraocular inflammation in any of our patients, and all 12 eyes had clear media on the postoperative visits. Scleral indentation performed in the operated eyes showed no change in the axial positioning of the IOL. After 1 month of follow-up, we found no IOL decentration or any other complications in any of the operated 12 eyes.

Summary

Fibrin glue-assisted sutureless posterior chamber IOL implantation is appropriate for eyes with deficient or absent posterior capsule, and this can be performed easily with the available IOL designs and instruments and with less surgical time. However, a longer duration follow-up might be necessary to judge the long-term functional and anatomical results of the procedure.