Eyeworld

EW INTERNATIONAL 114 March 2017 by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer uses the suprachoroidal drainage system to shunt aqueous, increasing uveoscleral outflow. The XEN gel stent, however, comes close to tradi- tional filtration surgery by shunting aqueous into the subconjunctival space, but is performed ab interno, freeing up all points of resistance. So the question is: is this good enough? The results are compelling. However, I believe that even though making use of transtrabecular, suprachoroi- dal, and filtrating mechanisms to reduce IOP lets us treat every type of patient, we still need trabeculecto- my," Dr. Jünemann said. Case for trabeculectomy For Dr. Jünemann, the exception- al results achieved through MIGS to lower raised IOP in open-angle glaucoma patients do not preclude the further implementation of trabeculectomy. In fact, there are scenarios in which he would choose trabeculectomy as the best choice for the patient. "The idea of com- pletely switching from a trusted ab externo procedure to MIGS is a true dilemma, because for me trabeculec- tomy has always been part of my ar- mamentarium for glaucoma surgery. I may be accepting of new ideas, but I still hold on to this valued proce- dure. MIGS is still very new." The American Glaucoma Society and U.S. Food and Drug Adminis- tration convened in 2014 to agree tions of 8–27% and medication reductions from 80–100%. 4 Dr. Jünemann elucidated that other MIGS devices like the iStent, Hydrus (Ivantis Inc., Irvine, Cali- fornia), Cypass (Alcon, Fort Worth, Texas), and AqueSys XEN gel stent (Allergan, Dublin, Ireland) showed promise but were not as well-doc- umented through clinical trials. One investigation in open-angle glaucoma patients presenting with IOP values between 22–38 mm Hg revealed a mean postoperative IOP of 15 mm Hg without medications using the iStent, 5 while the Hydrus achieved at least 20% IOP reduc- tion in 80% of the 100 study eyes with open-angle glaucoma at 24 months after combined cataract plus Hydrus implantation surgery. 6 Initial clinical experience with the Cypass micro-stent showed a mean reduction in IOP of 9.6 mm Hg and reduced medications in a study that combined the Cypass with cataract surgery in 167 eyes. 7 Finally, cataract surgery combined with the implan- tation of the XEN gel stent resulted in a postoperative reduction in IOP of below 18 mm Hg in 85% of 37 eyes with open-angle glaucoma. 8 "These MIGS devices each take advantage of different drainage options within the aqueous drainage meshwork. The iStent is a trabecular stent that reduces transtrabecular re- sistance. The Hydrus is a Schlemm's canal microstent, while the Cypass Trabeculectomy: Still relevant in the wake of MIGS Uriant bleb covering the cornea Small avascular bleb after mitomycin C-augmented trabeculectomy continued on page 116 Presentation spotlight While recognizing its advantages, a German specialist explains why MIGS devices cannot entirely replace trabeculectomy C hange is not always easy to embrace, particularly when your methods are tried and true, reliable and effective. But, the most stubborn nonbelievers cannot deny the stun- ning IOP relief achieved by micro- invasive glaucoma surgery (MIGS). Anselm Jünemann, MD, professor of ophthalmology, Rostock Univer- sity Eye Clinic, Rostock, Germany, discussed his 180-degree turnaround regarding the role of MIGS devices in modern glaucoma surgery, and why, despite the evidence, he can- not turn his back on trabeculectomy. "We have an abundance of new operative techniques in glaucoma surgery. The question is whether new techniques replace old ones or whether it is prudent to keep the old ones alongside the new, using them as we see fit, according to the level of success or failure we achieve with selected techniques," Dr. Jünemann said during a presentation he gave on the topic at the 114th Congress of the German Ophthalmological Society, which was held September 29 through October 2, 2016. The case for MIGS According to Dr. Jünemann, the facts speak loudest. In a prospec- tive open-label randomized study that used the iStent (Glaukos, San Clemente, California) in 62 eyes of 43 patients with primary open-angle glaucoma (POAG), pseudoexfolia- tion glaucoma, ocular hypertension, or secondary/post-traumatic glau- coma, the 3-year outcomes showed a sustained reduction in IOP, from mean preoperative 24.1 mm Hg, to a mean of 14.9 mm Hg at 36 months, and an excellent safety profile. 1 The mean pressure reduction of 8.5 mm Hg outdid the mean reduction of 4.1 mm Hg observed after a 3-year follow-up period in the Ocular Hy- pertension Treatment Study (OHTS), which examined the effect of topical ocular hypotensive medication in POAG patients, who had a mean preoperative IOP of 23.9 mm Hg. 2 Another prospective pilot study involved implantation of two trabecular micro-bypass stents in 39 open-angle glaucoma patients, achieving a significant and sustained reduction in IOP and medication over 18 months of follow up. 3 The mean unmedicated IOP decreased from 25.3 mm Hg preoperatively to 17.1 mm Hg at 13 months. In a published review on the iStent, the authors show the safety and efficacy of the iStent system based on the outcomes of randomized controlled clinical trials, revealing IOP reduc-

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