EyeWorld Asia-Pacific March 2016 Issue

59 EWAP DEVICES March 2016 or incapable of complying with topical medication; “in such cases MIGS as a standalone would make sense if the patient has mild or moderate disease.” All three experts agree that newer generations of MIGS are likely to result in regulatory approvals for standalone procedures, once those studies are undertaken. While scientifically many of the devices have the potential to be standalone procedures, there is also great potential for combining several of the MIGS procedures, Dr. Francis said. “We want to offer patients everything we can for IOP lowering short of a traditional filtering surgery,” he said. Phakic patients and high pressures Most surgeons will shy away from MIGS procedures when the patient has high IOP, “which is a mistake because those patients actually tend to do very well” with combined procedures, Dr. Francis said. “If you start with a pressure of 30 mmHg and your target is 18 mmHg, you may meet that very readily with a MIGS plus cataract or a MIGS as a standalone procedure.” Unresolved IOP in a phakic patient with visually significant cataract “should absolutely” be considered for a combined procedure, Dr. Rhee said, even in patients with higher IOPs. “I pursue the potential of removing the cataract and doing cataract/glaucoma surgery at the same time. Once surgical intervention is necessary, cataract/MIGS should be considered. It’s not trabeculectomy,” he said. “That’s where we need to go. My go-to procedure is cataract/ Trabectome,” although he may be in a minority. But for patients with elevated pressure and 20/20 vision (or even those with early disease), the treatment may not be as clear-cut, and a viable and modestly efficacious option is Trabectome, Dr. Rhee said (although non-MIGS procedures such as canaloplasty or deep sclerectomy should also be considered). Dr. Rhee considers cataract/MIGS in those with advanced disease, as it offers a safer option than traditional trabeculectomy. “The combined procedure reduces the IOP enough that it helps improve the safety profile of a trab, if we need to go there,” he said. Dr. Samuelson, however, is reluctant to consider combined surgery in patients with severe cases unless compliance and tolerance of medications has been established. “There will be a role for that down the road as more devices get approved and the regulatory handcuffs come off,” he said. “I think many MIGS devices will eventually be used as standalone procedures.” For example, Dr. Samuelson said the Ivantis Hydrus (Irvine, Calif.) provides two mechanisms of action that make it particularly attractive as a potential standalone device. Other transscleral MIGS procedures that will make the subconjunctival approach to glaucoma surgery safer, such as the Xen Gel Stent (AqueSys, Aliso Viejo, Calif.) or the InnFocus MicroShunt (Miami), are also being eagerly awaited for regulatory approval, Dr. Samuelson said. Similarly, the CyPass (Transcend Medical, Menlo Park, Calif.) and the iStent Supra (Glaukos, Laguna Hills, Calif.) will be “uniquely applicable in situations such as angle-closure glaucoma where we can’t use canal-based surgery,” he said. “I don’t think it will be that much longer before we’re discussing MIGS as an option before, during, or after cataract surgery. That’s not to say that trabeculectomy and tubes won’t be utilized. They certainly will, but we’ll have options at earlier stages in the disease to intervene surgically,” Dr. Samuelson said. Cataract procedures alone For patients with advanced open-angle glaucoma, cataract surgery by itself probably should not be a standalone procedure to control IOP, Dr. Rhee said. “Not even the most avant-garde glaucoma specialists would look at a patient and tell them they need a lower pressure so we’re going to only remove their lens because of the risk of an IOP spike.” Plus, he said, 20/20 with a crystalline lens is not the same visual quality as 20/20 with an IOL. When he’s removed a lens primarily as a pressure-lowering move in cases of phacomorphic glaucoma and the patient had good vision, anecdotally patients note the loss of accommodation or the ability to see near. “This is just my sample of a handful of people,” he said. “But should standalone cataract surgery be considered? Yes.” Deciding on a procedure depends on how difficult it is to manage IOP and where the baseline levels were, Dr. Francis said. One medication and well controlled? Cataract surgery alone may be adequate. “But if they’re on two meds and pressure is not well controlled, then I’d definitely do cataract plus MIGS. Cataract surgery by itself does have a place, but it can also be dangerous to assume that just doing cataract surgery is going to control their glaucoma.” Plus, surgeons may “lose an opportunity” to further reduce the IOP by only performing cataract surgery, he said. EWAP Editors’ note: This article was written before Allergan’s purchase of AqueSys was completed. Dr. Francis has financial interests with Beaver-Visitec International (Waltham, Mass.) and NeoMedix. Dr. Rhee has financial interests with Glaukos and Ivantis. Dr. Samuelson has financial interests with AqueSys, Glaukos, and Ivantis. Contact information Francis: bfrancis@doheny.org Rhee: dougrhee@aol.com Samuelson: twsamuelson@mneye.com