Eyeworld

EW GLAUCOMA 100 February 2018 pediatric patients who come into adulthood with Axenfeld-Rieger syn- drome, who have never had angle surgery, the more of the angle that is opened, the better the response. "For years, these cases were successfully treated with ab externo canaloplasty. Now we employ ab interno, sparing procedures like GATT, Trabectome, and Visco360 for well controlled uveitic cases," Dr. Harasymowycz said. Dr. Harasymowycz thinks that surgeons should familiarize them- selves with different options and gravitate toward procedures and devices that they think work best in their hands. "Ophthalmologists should get to know a number of different techniques that they can use in different patient settings," he said. "Then they should use their ex- cision of choice and eventually their implant of choice. Reimbursement is something we have to keep in mind and it is different everywhere, even here in Canada, although we are moving toward a universal code. GATT can be performed by using a 5.0 prolene suture, which is not expensive. So if you are searching for trabecular excision models, which are extremely cost effective, GATT would be the one. It performs well when exposing more collector channels, although this can cause increased hyphema. Still, the more collectors that are open, the more lowering you can potentially get, which is what makes GATT so effec- tive. What is exciting, at least for Eu- rope and Canada, is using multiple devices, like iStents that generally get a good response when targeting collector channels but have shown even better outcomes when more than one is implanted." Best choice? Safety Can anyone boil down all of the current MIGS options to one "best" approach? Could things have finally gotten easier? According to Doug- las Rhee, MD, professor and chair, Department of Ophthalmology and Visual Sciences, University Hospitals Eye Institute, Cleveland, the answer is "no." When it comes to choos- ing an approach to the TM, caveats abound, however, the diversity of treatment alternatives gives excel- lent options to choose from for the broad spectrum of glaucoma pa- tients. "There are numerous factors to consider in our choice of glauco- ma treatment, however, my person- al preference is always safety first, although nothing here is carved in stone," Dr. Rhee said. "Every patient and every physician is going to have a different risk/tolerance profile. MIGS procedures offer more modest pressure reducing results than tra- ditional glaucoma surgery (trabe- culectomy), however, they have the advantage of a safer risk profile. This makes MIGS suitable and desirable for patients with mild to moderate disease. MIGS are not that much dif- ferent from cataract surgery, which is one of the safest things we have out there in medicine today." In keeping with his safety first approach, Dr. Rhee's choices are as follows: consider MIGS first, coupled with cataract surgery, wherever pos- sible, as the combined procedures are safe and the pressure-lowering effects amplified. Trabeculectomy will be his go-to in pseudophakic eyes or in the absence of visually significant cataract, particularly in the presence of elevated pressures. Patients with controlled IOP may simply need cataract surgery, how- ever, those on several anti-glaucoma medications would benefit from the addition of a MIGS procedure. "In actuality, if the setting is right, I have replaced trabeculecto- my with cataract/MIGS as my first line procedure, and I will use the above algorithm to make further decisions," Dr. Rhee said. "The ad- vantage of doing it this way is that even though the chance of success for lowering IOP is not as high as trabeculectomy, it is the safest. If it does fail and you need to perform trabeculectomy after all, you are now doing a trabeculectomy in an eye that is pseudophakic, so the risk of having significant complica- tions from hypotony is lower. It is rare that the pressure does not go down—it will come down some, maybe just not enough—and if that is the case, at least the opening pres- sure when we do trabeculectomy is at a lower level. "Among MIGS devices and pro- cedures, there is a paucity of level 1 prospective randomized controlled trials, but there are a few good case series that show them to be very safe procedures, with recovery rates that are faster than trabeculectomy," Dr. Rhee continued. "Cataract surgery combined with Trabectome, iStent, and KDB is appropriate for adults with higher pressure glaucoma as seen in primary open angle, pseu- doexfoliation, and pigment disper- sion. These would not necessarily be effective or appropriate in patients with low pressure glaucoma, if your goal is to lower the pressure further. If your goal in a low pressure glau- coma patient is to prevent a pres- sure spike, it is OK to do any one of those three, but it is not going to get the pressure down. The CyPass Micro-Stent [Alcon, Fort Worth, Tex- as], although it is still too early to tell, may have the potential to lower IOP in individuals with low tension glaucoma. Trabeculectomy, the (former) gold standard, is extremely effective in patients who have low tension glaucoma that you want to lower even more. Trabeculectomy is the only procedure that does this relatively reliably. There are a lot of caveats, but it is a complicated matrix." Dr. Rhee finds GATT and canaloplasty technically challeng- ing. GATT, in his experience, is associated with a high incidence of visually significant hyphema as well. "We'll see what the long-term results of GATT are," he said. "It appears with the 2-year data being reported as though the success rates might be a little better than those achieved with the mechanical trabeculotomy that was done back in the 1950s and 1960s." Future data will give clinicians the benefit of better guidelines to be able to individualize treatments in glaucoma patients. When it comes to MIGS, unfortunately, physi- cians are still guessing and hoping for positive long-term safety and efficacy outcomes. The low number of comparative prospective random- ized trials, lack of trial standardiza- tion and cost effectiveness data, and largely incomplete, often subjective patient selection criteria limit any real sense of these devices. EW Editors' note: Dr. Harasymowycz has financial interests with Alcon, Allergan (Dublin, Ireland), Glaukos, and Ivan- tis. Dr. Rhee has no financial interests related to his comments. Contact information Harasymowycz: pavloh@igmtl.com Rhee: douglas.rhee@uhhospitals.org Deciding continued from page 99 Beginning MIGS: How to choose a device Robert Noecker, MD, discusses the selection of a MIGS device for cataract surgeons who want to learn to perform MIGS. EWReplay.org

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