April 2013

 

CATARACT

 

Tools & techniques

Microbulldog silicone assistant for intrascleral haptic fixation of IOLs


by Steven G. Safran, MD
 

More 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

 

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.

Figures 4, 5, 6: Microbulldog silicone assistant is guided onto the haptic by inserting the haptic into the tip of the needle and sliding the MSA down over the haptic.

Figure 7: MSA is now securely on tip of haptic.

Figure 8: Even pulling on the IOL will not cause slippage of the haptic through the MSA. It is very secure.

Source (all): Steven G. Safran, MD

In 1991, when I was a cornea fellow at Duke University, I came up with a design for a simple device called a "micro-bulldog." 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 trailing haptic. While this trailing haptic is placed in the eye and passed to a microforceps to externalize it through a sclerotomy, the surgeon needn't worry about the first leading haptic slipping back into the eye. The focus can be maintained on the task at hand.

After the second trailing haptic is externalized the silicone assistant can be easily slid off the haptic and the surgery completed. This is a simple, inexpensive method that can be used by any surgeon with access to a butterfly cannula, a scissor, and a 25-g needle. It takes very little skill and even less time to perform and should reduce some of the anxiety associated with performing the scleral fixated haptic or "glued in IOL" procedure. George Beiko, FRCSC, has advocated taking the silicone sleeve from an MST (Redmond, Wash.) or Mackool capsule retractor and sliding it over the lead haptic to hold it in place during surgery. These retractors can be quite expensive however, and manipulating the silicone sleeve over the haptic can be a bit delicate. The homemade microbulldog silicone assistant method suggested here offers the advantage of being very inexpensive to fashion and very easy to apply to the IOL haptic during surgery as it is "pre" loaded onto a 25-g needle, which serves to guide it over the haptic very gently when needed in order to give a hand to the surgeon born with only two arms.

Editors' note: Dr. Safran is in private practice in Lawrenceville, N.J. He has no financial interests related to this article.

Contact information

Safran: safran12@comcast.net

Microbulldog silicone assistant for intrascleral haptic fixation of IOLs Microbulldog silicone assistant for intrascleral haptic fixation of IOLs
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