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59 EW FEATURE November 2016 • Complicated glaucoma surgery management a patient subsequently at risk for an additional surgery to remove a progressive cataract," Dr. Bacharach continued. "In that situation, for ex- ample with trabeculectomy, having to go back and remove a cataract, the cataract surgery itself induces risk that the initial glaucoma surgery could fail." Though cataract surgery alone has been shown to have an IOP-low- ering effect, 1 Steven Sarkisian, MD, clinical professor of ophthalmology, and director of the glaucoma fel- lowship, Dean McGee Eye Institute, Oklahoma City, said it is not long lasting. "I think that if a patient is on medication and has a coexisting cataract, failing to do something to address the glaucoma at the time of cataract surgery, given our multiple options now, is a lost opportunity," Dr. Sarkisian said. "You're doing patients a real disservice if you don't at least make them aware of the option." iStent: Four years later Both Drs. Bacharach and Lewis have been implanting the iStent (Glaukos, San Clemente, California), the first U.S. Food and Drug Ad- ministration-approved MIGS device designed to bypass the trabecular meshwork, for upward of 10 years, being involved in its clinical trials. Dr. Sarkisian has been using the iStent since its 2012 FDA approv- al. Research has shown the iStent to have a strong safety profile and IOP-lowering effect compared to cat- aract surgery alone, and Dr. Bacha- rach said his clinical experience has demonstrated the same. Dr. Lewis said he likes the iStent but noted that it's not for everyone. Patients with narrow or closed-angle glaucoma are not good candidates for the procedure, he said. "I need to have good visibility of the angle and I need to be able to position them well," Dr. Lewis explained. Surgeons face a learning curve with the iStent as well. "The key to success with the iStent is to get over the learning curve as fast as possible, which means that on the first day you perform the iStent, you should consider doing three to five surger- ies," Dr. Sarkisian said. "The second day you do the iStent, make sure it's about a week or two later and you do the same thing. You need to do a high volume of cases up front in or- der to get over the learning curve." As for surgical pearls, Dr. Sarkisian said having an even hand with the gonioprism, not pushing too hard or too lightly is important to avoid striae in the cornea and air bubbles. He said the incision should not be made too posteriorly, so as to avoid hitting blood vessels, because blood under the gonioprism could obscure the view. The anteri- or chamber should not be over or under inflated, and positioning the patient's head and the microscope to give a direct view of the angle are important. "You need to see well and do whatever it takes to get there," Dr. Sarkisian said. Dr. Lewis recalled a patient with arthritis, which made it difficult to administer glaucoma drops and thus made her a good candidate for a MIGS procedure at the time of cataract surgery. Severe spine and back issues, however, meant a lot of manipulation to get this woman in the appropriate position for iStent surgery. Arsham Sheybani, MD, assis- tant professor, Washington Univer- sity School of Medicine, St. Louis, said he coaches residents and fellows to relax their hand, pulling back to- ward themselves slightly just before releasing the stent. "It almost looks like you're out of the canal, but you have released all tension so you're not turning the eye away from you," he said. "You're sliding it into the canal instead of hitting the outer wall. ... More often than not though, you see people trying to push the stent in instead of guiding it in nicely." Dr. Lewis said taking a video of some of your first iStent procedures can help you learn from your mis- takes and enhance your skill. When to implant iStent—before or after cataract surgery—is also a consideration. Dr. Bacharach said the decision is situational for him. Before cataract surgery, the cornea is clear and unclouded, plus you might not have to open another viscoelas- tic tube, he said. Implanting after cataract surgery can be useful in eyes where the angle is a bit narrower at the start. "The suggestion I have if you're going to implant it before you do the cataract surgery is to implant it after doing the capsulorhexis. The potential pitfall of doing the MIGS first is that if you get a little bleed- ing, it can make the capsulorhexis more challenging," Dr. Bacharach said. A patient failed to tell Dr. Lewis he was on tamsulosin, which resulted in floppy iris syndrome as he put the stent in with eventual iris prolapse. After that case, Dr. Lewis said he prefers to place the iStent after cataract surgery. Dr. Sarkisian also said he prefers to place the iStent after cataract surgery when the eye is soft and because any blood in Schlemm's canal can help identify collector channels, and targeting these could improve IOP reduction. Constance Okeke, MD, MSCE, Virginia Eye Consultants, Norfolk, Virginia, recommends placing the iStent before cataract surgery be- cause it allows for a better view. She uses a 15-degree blade with a 1.5- mm incision at its widest diameter because it minimizes egress out of the wound, and allows you to main- tain a well-formed chamber with EyeWorld Monthly Pulse EyeWorld Monthly Pulse is a reader survey on trends and patterns for the practicing ophthalmologist. Each month we send an online survey covering different topics so our readers can see how they compare to our survey. If you would like to join the hundreds of physicians who take a minute a month to share their views, please send us an email and we will add your name. Email carly@eyeworld.org and put "EW Pulse" in the subject line. Poll size: 108 continued on page 60

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