EyeWorld Asia-Pacific September 2021 Issue

FEATURE EWAP SEPTEMBER 2021 13 bypass the trabecular meshwork have “considerably lower” complication rates than other MIGS, because they cannot develop hypotony being always limited by episcleral venous pressure. “Complication rates are reassuringly low for both iStent Q laukosR and ydrus Q ÛantisR,» he said. In contrast, Dr. Pereira detailed how the CyPass microstent (Alcon) was withdrawn from the market after a significant increase in endothelial cell loss noted in eyes with the implant beyond 4 years. Ike K. Ahmed, MD, Canada, also shared some anecdotes about MIGS failures, typically occurring when not prepared or setup properly, with problems involving visualization, surgical technique, and/or anesthesia. e shared some tips and preferences to avoid problems, such as performing MIGS before removing a cataract to reduce the risk of blood reyuÝ, keeping the bed in reverse Trendelenburg during surgery to avoid increased venous tone, having OVD ready and using enough administered focally to push heme proÝimallyp although eÝcessiÛe Ûiscoelastic into the anterior chamber can also produce complications such as, in one case, a fairly large dialysis—and, critically, having a good view to place implants in the correct location. “Although there are some cases where MIGS can sometimes go wrong, fortunately in most cases these are not typically serious problems but have to be managed appropriately,” Dr. Ahmed said. Back to trab *roÛided with this conteÝt, Leonard Yip, MD, Singapore, asked “when is it time to go back to doing a trabeculectomy?” Focusing on factors related to the patient’s eye, Dr. Yip said that trabeculectomy becomes the option when large IOP pressure reductions most MIGS currently cannot deliver are required; when angle or anterior chamber abnormalities make MIGS unsuitable; when use is off-label for MIGS; and following MIGS failure. “Fortunately, severe MIGS failures requiring repeat surgery are not common,” he said. º oweÛer, trabeculectomy or reviving the trabeculectomy can be sight saving in such cases.” Back to MIGS Importantly, “most MIGS procedures are not designed to replace trabeculectomy; many still try to use this comparison and that½s the first fallacy of MIGS,” Dr. Ahmed said, returning to discuss optimizing MIGS procedures. “That’s not the purpose of MIGS.” The purpose of MIGS, he said, is to delay the need to go on to trabeculectomy bleb surgery. e described the ", <" study which compared phaco with ydrus and phaco alone over 5 years and showed that, despite pressures being similar, the patients who had the device were on fewer medications, less need to go on to further glaucoma surgery. One of the more important factors to optimize MIGS is patient selection. Critical factors for optimizing MIGS are patient selection, eye and scope positioning, finding the optimal area and location for implantation of the selected MIGS device, and prevention of hyphema and early postop management. Less under the control of the surgeon at the time of surgery are distal outyow resistance or function and tissue healing are also significant Ûariables. e then described more recent developments in the field of -phe said eÝcimer lasers have come back, able to create precisely located, precisely sized ostomies that are more likely to stay patent than those created with a blade or tearing with a suture; the move toward more combination MIGS, relying on multiple mechanisms to increase the pressure lowering effect; the “hot off the press” use of femtosecond lasers to create micron-accurate, customized channels through the trabecular meshwork, with the added benefit of " T guidance and the possibility of retreatments at any time without going to the operating roomÆ and finally blending MIGS and trabeculectomy features as with the Xen Gel-Stent (Allergan) and *reseryo icroshunt (-anten). In the end, Dr. Ahmed said that there most certainly are “things happening in the MIGS space; I recommend paying attention.” EWAP Editors’ note: Dr. Makornwattana, Dr. Perera, Dr. Yip, and Dr. Ahmed have interests with various ophthalmic companies. Dr. Lee disclosed no relevant financial interests. Eye of a 50-year-old glaucoma patient who successfully underwent MIGS despite corneal injury and conjunctival hyperemia. Dr. Makornwattana opted for MIGS to give the patient’s corneal surface time to recover before proceeding with glaucoma surgery. Source: Manchima Makornwattana, MD