A Vertical Leap of Faith
Saving the few remaining zonules, repairing the pupil, and addressing glaucoma in a case for the ages.
A 67-year-old patient presented with severe blunt trauma from a bungee cord injury to the eye. He had significant crystalline lens dislocation, with the lens sitting vertically in the anterior vitreous cavity and only a few intact zonules; an atonic, fixed pupil; and traumatic glaucoma with an IOP of 50 mm Hg.
THE CRYSTALLINE LENS
The first step in this complex case was to manage the crystalline lens. I placed a 23-gauge trocar to access the anterior vitreous cavity and injected triamcinolone acetonide to identify vitreous, some of which had prolapsed into the anterior chamber. With anterior infusion and pars plana cutter insertion, I evacuated the anterior segment and the anterior vitreous cavity of vitreous with appropriate vitrectomy.
Using scleral depression, I was able to bring the crystalline lens into view. I positioned multiple iris hooks, to be used temporarily to hold the capsulorrhexis edge during creation of the anterior capsulotomy. With a blunt Q-tip, scleral depression was again used to bring the lens into view, and microsurgical forceps (MicroSurgical Technology) were utilized to puncture the anterior capsule and initiate the capsulorrhexis (Figure 1).
I continued using microsurgical forceps to initiate the tear, hold the lens up, and propagate the capsulorrhexis in a counterclockwise fashion. Probably the most crucial step of this procedure was maintaining anterior levitation while creating a continuous curvilinear capsulorrhexis (CCC) that was centered, ideally 5.5 mm in size, and round. All efforts were made to preserve the capsular bag. I used a second pair of microsurgical forceps to hand off to the next to allow propagation of the capsulorrhexis (Figure 2).
Iris hooks were used on the partially torn edge of the capsulorrhexis to hold the lens in place and provide countertraction. I continued with the capsulorrhexis, carefully trying to again ensure that it was round and centered and that enough of an anterior capsule leaflet was present to support the capsular bag with iris hooks and later with capsular tension segments (CTSs). I then converted to capsulorrhexis forceps and performed a standard capsulorrhexis in a curvilinear fashion, fortunately creating a complete, centered CCC (Figure 3). Throughout this step, I was asking myself, “When will I be converting to intracap or pars plana lensectomy?” Miraculously, however, I was able to achieve a good CCC.
After performing viscodissection to separate cortex from capsule, I proceeded with the use of capsular tension devices. A PMMA capsular tension segment (CTS; Morcher) with two end eyelets and a central eyelet was used to support the capsular bag. I slid the CTS into the capsular fornix with the use of a Sinskey hook (Figure 4).
Using the force of the iris hook, which at this point was inverted, I placed the iris hook through the fixation eyelet of the CTS. This was repeated with another CTS on the other side. An advantage of a CTS is that it provides broad support of the capsular equator. The iris hook was used again, upside-down through the eyelet, almost like a coat hanger hanging up a coat, to support the capsular bag (Figure 5). A capsular tension ring (CTR; Morcher) was used to provide circumferential support of the capsular bag, exerting centrifugal forces to provide tension on the bag and the posterior capsule.
Next, hydrodissection and hydrodelineation were performed. This patient had a soft to moderately hard lens, so hydrodelineation was helpful for separating the endonucleus and epinucleus (Figure 6). Then, using phaco chop techniques, I basically created an essential crack and then hemi-flipped each of the heminuclei (Figure 7).
The benefit of having CTSs in place is that they help to preserve the capsular bag, hold it in place, and create tension on the posterior capsule to reduce the risk of the posterior capsule being too labile and potentially coming forward. Other concerns to be mindful of here include fluid misdirection syndrome and/or vitreous prolapse. Injection of viscoelastic prior to removal of the handpiece can help to prevent this. Use of vitrectomy instrumentation to perform bimanual irrigation/aspiration is useful for removing all cortex (Figure 8).
I then loosened up the iris hooks and prepared the CTS for suture passage (Figure 9). I did a little more vitrectomy anteriorly, just under the iris, to ensure that I freed the anterior segment of any vitreous. A scleral groove was made tangential to the limbus 1.5 mm posterior to the scleral spur, which is identified by the end of the blue zone (Figure 10).
Using a pair of microsurgical forceps, I took one CTS, brought it into the anterior chamber, and turned it on its side. A 25-gauge hypodermic needle was inserted through the scleral groove, under the iris, and above the capsular bag to dock a double-armed 7-0 Gore-Tex suture (W.L. Gore & Associates), which was threaded through the central eyelet of the CTS (Figure 11).
I placed a second 25-gauge needle, about 2 mm adjacent to the first pass, to capture and dock the second arm of the 7-0 Gore-Tex suture (Figure 12). I then proceeded to the second CTS and did the same thing, again with a 25-gauge needle. A 25-gauge needle works well for 7-0 Gore-Tex, which is the smallest Gore-Tex suture available. Gore-Tex is my preferred material, as I have found the stability, the lack of suture breakage in the long term, and the support to be ideal.
Next, a slipknot was created, allowing me to titrate the tension of that suture prior to finalization of the knot. Once this was done on both sides, I placed a one-piece acrylic IOL in the capsular bag (Figure 13), and I locked the suture once I was happy with the tension and centration of the lens. It is important to rotate the knot into the sclera to prevent extrusion or erosion of the suture material through the conjunctiva.
My attention was then directed to the iris. The patient had an atonic, dilated pupil that was about 9 to 10 mm in diameter and unreactive. I used a 10-0 polypropylene suture on a CIF-4 needle (both Ethicon), and, with a pupillary iris cerclage technique, used microsurgical forceps to bring the iris to the long, curved needle. Using a running baseball stitch, I passed the suture all the way around the pupil margin (Figure 14). A couple of paracenteses could also be created to do this in quarters or in thirds. Docking the needle as it comes out helps avoid trapping any of the needle in the cornea.
Using the second arm of the suture, I passed the needle to the superior side of the pupil in a counterclockwise fashion (Figure 15). I could then proceed to place the suture across the entire superior pupil margin, coming out through the main incision and docking it out, and I repeated this step for the remainder of the pupil. The use of microsurgical forceps is helpful to get the iris to the needle and avoid excessive needle manipulation in the anterior chamber.
At this point, I could then tie the suture outside the eye and slide it into the eye using a microsurgical knot tier—a technique that has been named The McAhmed. I aimed for a 3.5-mm pupil to reduce the significant glare this patient had preoperatively and would still have without treatment of the pupil. I locked the knot in place, again using the knot tier to bring the knot into the eye, and then cut it with microscissors to create a round and smaller pupil (Figure 16).
Next, it was time to address the patient’s glaucoma. I chose to place an Ahmed Glaucoma Valve (New World Medical), as I did not feel a combined microinvasive glaucoma surgery procedure would be enough for the patient’s high IOP and withstand the complexities of the surgery. I wished to avoid trabeculectomy, as I felt the inflammation and extent of the surgery would put it at increased risk for failure.
Using a 6-0 polypropylene suture (Ethicon) placed in a horizontal mattress fashion, I did one single pass to both eyelets of the Ahmed glaucoma plate (Figure 17). I tied the knot so that it was automatically placed under the body of the plate to have it buried (Figure 18). Cutting that polypropylene suture after the knot is locked secures its position.
The Ahmed glaucoma plate was placed 9 mm posterior to the limbus in the superotemporal quadrant. I used a 22-gauge hypodermic needle, 4 mm back from the limbus, and passed it tangentially along the scleral surface. I then entered the eye at the scleral spur, pointing the needle very steeply posteriorly to get the tube ideally positioned at the iris plane (Figure 19), and trimmed the tube to the adequate length. This resulted in patchless, intrascleral tunnel placement of the tube.
I placed the tube through the scleral groove tunnel created in the anterior chamber (Figure 20). Typically, this is done without the need for a scleral or corneal graft. The conjunctiva was closed with fibrin glue, and 7-0 microsutures were used to anchor the conjunctiva superiorly and inferiorly.
This procedure was performed under topical anesthesia with some posterior sub-Tenon lidocaine. In this highly complicated repair, I was able to manage the patient’s subluxed lens; the atonic, fixed, dilated pupil; and traumatic glaucoma. Preservation of the capsular bag was important to ensure ideal positioning of the IOL, with support from the capsular tension devices and Gore-Tex sutures.
Iqbal Ike K. Ahmed, MD, FRCSC
• Assistant Professor and Director of the Glaucoma and Advanced Anterior Surgical Fellowship, University of Toronto, Canada
• Chief Medical Editor, Glaucoma Today
• email@example.com; Twitter @IkeAhmed
• Financial disclosure: Consultant (Alcon, MicroSurgical Technology, New World Medical, W.L. Gore & Associates)