New Guide Needles for Yamane Intrascleral Haptic Fixation Technique






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NEW GUIDE NEEDLES FOR YAMANE INTRASCLERAL HAPTIC FIXATION TECHNIQUE


Brandon D. Ayres, MD


Implantation of a posterior chamber intraocular lens (IOL) in the absence of capsular support can be a challenging surgical procedure. Only a few IOL designs can be adapted to suture fixation. Durability issues with polypropylene suture, which is commonly used for suture fixation, can lead to repeat dislocation after several years, and large incision sizes are needed for single-piece polymethylmethacrylate (PMMA) IOLs. In some instances, the IOL material can degrade or opacify over time. With all these complicating factors, surgeons continue to seek a straightforward, safe, and durable option for posterior fixation of an IOL in the absence of capsular support.


In 2014, Shin Yamane described a technique for placement of an IOL in which 27-gauge needles were used to guide the haptics of a 3-piece IOL into a scleral channel. The terminal ends of the haptics were then melted using low-temperature cautery to create a terminal bulb. The bulb prevents the haptic from prolapsing back through the scleral channel.1 Using this sutureless technique, many modern 3-piece IOLs can now be fixated in the absence of capsular support.


Advantages/Disadvantages


The Yamane technique has several advantages over other fixation methods. A primary benefit is the use of small, self-sealing incisions. In most cases, the largest incision required would be between 2.75 to 3.2 mm, depending on the IOL selected. The smaller incisions help avoid hypotony while providing for self-sealing wounds that can shorten surgical times. Added benefits stem from the removal of complex scleral incisions.


Alternatively, when using suture fixation or glued IOL techniques, multiple scleral incisions or flaps are typical. The Yamane technique requires only two 27- or 30-gauge scleral wounds to guide the haptics into the scleral channels. The needle-created scleral incisions are transconjunctival, so there is no need for conjunctival incisions. The option to use hydrophobic acrylic IOL material is of great advantage vs other sutured IOL techniques. Often, patients needing secondary IOL fixation have accompanying ocular pathologic processes and may require additional retinal or corneal surgery either concurrently or after IOL placement. The hydrophobic acrylic material does not interact with silicone oil, nor does the optic opacify if exposed to air or surgical gas (Figure 70-1).2


The apparent simplicity of the Yamane technique is its greatest strength and its greatest challenge. When performed by an experienced surgeon, the technique is quick and efficient, but there are several nuances to the technique that are not obvious. If the technique is not meticulously followed, the procedure can be quite challenging. One of the biggest frustrations is decentration or tilt of the IOL. If the scleral incisions are not created perfectly, the optic can end up significantly decentered. Adjustments to centration can be made by asymmetrically adjusting the extrascleral haptic length, but this does not always solve the problem, and a new sclerotomy will need to be made. Tilt of the optic can also be seen if the 2 scleral channels are not created uniformly or are not made 180 degrees across from each other.3 To make the technique more reproducible, several industry partners have devised centration, incision, and needle guides to take some of the guess work out the Yamane technique for IOL fixation. MicroSurgical Technology (MST) produces a disposable convenience pack to help surgeons demystify haptic fixation. The kit includes everything needed to perform the procedure other than the IOL (Figure 70-2).



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Figure 70-1. IOL exchange using Yamane technique combined with Descemet’s stripping endothelial keratoplasty. The hydrophobic acrylic material of the implant being used will not opacify when exposed to air or surgical gas.




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Figure 70-2. Highlights of the MST Surgical Convenience Pack. (A) The MST needle compared to a traditional needle. (B) Using a marking template to locate 2 mm from the limbus on the visual axis. (C) The needle affixed onto the handle. (D) The needle released after the activation of the slide on the handle. (E) Using the marker to place the secondary needle. (F) The MST Scleral Fixation Convenience Pack without the cautery device. ([A, C, F] Reprinted with permission from MicroSurgical Technology.)

Jan 13, 2020 | Posted by in OPHTHALMOLOGY | Comments Off on New Guide Needles for Yamane Intrascleral Haptic Fixation Technique
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