Reply : Scleral fixation (2006)

Our approach to scleral fixation does represent a modification of the traditional triangular flap technique, but we believe it offers several advantages not inherent in the traditional approach. The tunnel provides a larger surface area, which facilitates suture passage for an ab interno or ab externo approach. It appears to be easier to dissect than a triangular flap and requires no sutures for closure. Although the construction of 2 tunnels is more time consuming than a procedure in which the suture knot is buried through rotation of a full-thickness scleral pass, it is no less efficient than the dissection of 2 triangular flaps. We currently prefer not to rotate knots because of the possibility of suture breakage. In addition, the larger 9-0 and 8-0 recommendations for suture gauges may further impede knot rotation secondary to the larger knot size. The technique does require 2 suture passes that are initially placed through the full thickness of the dissected sclera, including the roof. These punctures appear to heal, as would be the case with any suture pass through scleral tissue, and the knot has not eroded or poked through these perforations since it appears to lie midway between the perforations under nonperforated sclera. Tying the sutures allows the knot to slide under the protection of the roof, and achieving adequate tension has not been an issue. We do recommend not tightening the sutures excessively and perhaps leaving some laxity to avoid cheese-wiring through the scleral bed. In our article, we presented one procedure only (scleral fixation of a large aniridia IOL); however, the tunnel technique can be used for any small-incision IOL or for a procedure that does not require incisions such as fixation of a dislocated IOL or repair of an iridodialysis. The large, temporal clear corneal incision used for the aniridia IOL is not connected with the scleral tunnel. Suture closure of the clear corneal incision incorporates relatively superficial suture passes compared with the depth of the sclerally fixated 9-0 polypropylene (Prolene) sutures. In addition, the scleral sutures are 1.0 mm posterior to the surgical limbus and thus an adequate distance from the clear corneal sutures. Compromise of the sutures, IOL, or tunnel has not been a problem, especially since the tunnel does not enter the anterior chamber. In eyes that are hypotonus and have large incisions or, for that matter, any incision, we recommend placing an anterior chamber (AC) maintainer or pars plana infusion port to avoid complications such as choroidal effusions or hemorrhages. The drawings in our article did not show the AC maintainer to simplify the image; however, it was mentioned in the technique description. The use of a scleral tunnel for scleral fixation is one more technique for surgeons to consider. As with many of our surgical techniques, we believe it represents a small incremental improvement of previous methods and we encourage surgeons to try it. In an upcoming issue, we will describe a further variation of this technique that eliminates the need for conjunctival dissection. We thank Baykara for taking the time to comment on our paper and we appreciate his contribution to this discipline within ophthalmology.