EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/119916
28 EW CATARACT April 2013 Tools & techniques Microbulldog silicone assistant for intrascleral haptic fixation of IOLs by Steven G. Safran, MD M ore interest has been brewing in the technique of intrascleral haptic fixation for the placement of secondary IOLs without capsule support and for the rescue of subluxed and dislocated primary IOLs. The procedure involves dissection of opposing scleral flaps and creation of a sclerotomy through the ciliary sulcus, through which each of the IOL haptics are received, externalized, and then incarcerated into a small scleral tunnel created adjacent to the dissected flap. The technique avoids potential issues related to late suture breakage of sclerally fixated IOLs. Three to five-year follow-up has demonstrated few if any late complications. The procedure is somewhat challenging in that it requires temporary fixation of the first leading haptic outside of the globe while the second trailing haptic is passed from one instrument to the other. A recent article by George Beiko, FRCSC, in the Journal of Cataract & Refractive Surgery described the use of a silicone sleeve from an iris or capsule hook to help secure the leading haptic outside of the sclerectomy temporarily while the trailing haptic was positioned. In this month's column, Steven G. Safran, MD, describes an ingenious, simple, and inexpensive method of creating a similar temporary "bulldog clamp" to facilitate the intrascleral haptic fixation technique. I am confident that surgeons currently performing this technique, and surgeons considering it for their future cases, will find this article extremely useful. Richard Hoffman, MD, Tools & techniques editor I n 1991, when I was a cornea fellow at Duke University, I came up with a design for a simple device called a "microbulldog." This was a miniature soft silicone clamp that was designed to hold the 10-0 prolene used for scleral suturing of the IOL securely and temporarily during sutured in lens cases combined with penetrating keratoplasty. I was doing a lot of scleral fixated posterior chamber lenses combined with corneal grafts and found that I achieved better centration and positioning of the sutured IOL in an eye that had a formed AC and normal IOP rather than when it was hypotonous. The "microbulldog" would hold the 10-0 prolene that was passed through the sclera under tension while I completed the suturing of the cornea graft. After the graft was completed, the anterior chamber was reformed, the eye firmed up, the microbulldog removed, and the implant finally sutured in place by scleral fixation. When I started doing intrascleral haptic fixation of IOLs in the absence of capsular support, it became clear very quickly that it was time to resurrect the microbulldog. After externalizing the leading haptic through a sclerotomy, it is much easier to place the trailing haptic in the eye and feed it to an instrument to externalize it if an assistant is holding the first, lead haptic in place. Without this assist, the lead haptic can slip back into the eye, and it is pretty easy at that point to drop the lens onto the retina. Most of us who do this surgery don't have an assistant we trust to gently hold that leading haptic without damaging it so that the surgeon can focus all of his attention on the trailing haptic. Here is a simple and inexpensive method of creating a microbulldog silicone assistant (MSA) to "cover your back." All that is needed is a butterfly cannula, a 25-g needle, and a scissor. First, the butterfly cannula tubing is cut to create a fresh edge. Then, the 25-g needle is passed through the tip to engage the wall of the silicone cannula (Figure 1). At this point, a scissor is used to cut the tip of the silicone tubing almost flush with the needle, amputating this tip (Figure 2). The microbulldog is now loaded onto the 25-g needle and set aside (Figure 3). After the lead haptic of the secondary IOL is grasped and externalized through a sclerotomy, the 25-g needle with the microbulldog is brought onto the surgical field. The haptic is engaged within the lumen of the 25-g needle (Figure 4), and the microbulldog is then slid down over this haptic (Figures 5 and 6). At this point the silicone assistant is in place and will hold the haptic firmly (Figure 7). The shape of this tip is designed so that a great deal of pulling force can be resisted without damaging the haptic or slipping. The surgeon can now focus on the continued on page 30 Figure 1: A 25-g needle is placed through the edge of a cut butterfly catheter tubing. Figure 2: Tubing is cut close to the edge where the needle is inserted to amputate the tip Figure 3: The microbulldog silicone assistant is now "locked and loaded" and ready for use.