EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/129516
May 2013 Glaucoma February 2011 challenges/MIGS EW FEATURE 39 AqueSys glaucoma implant offers new way to bypass outflow obstructions and lower pressure by Ellen Stodola EyeWorld Staff Writer The device operates in the subconjunctival space and is a minimally invasive procedure A queSys (Aliso Viejo, Calif.), an ophthalmic company specializing in glaucoma treatment, is currently developing an implant, which, unlike other microinvasive glaucoma surgery (MIGS) procedures, utilizes the subconjunctival space to minimize pressure issues and improve outflow. Although approved around the world, it is still awaiting FDA approval in the United States, but shows potential for the future. The implant is designed to bypass all potential outflow obstructions, and it would provide longterm IOP control, which could help reduce glaucoma progression in patients. The device is designed to be an improvement over current treatment for glaucoma patients. The AqueSys implant is made from a gelatin material. Combined with a minimally invasive procedure, this would ideally have a lower complication rate. Ron Bache, CEO of AqueSys, commented on the device, its progress so far, and goals for the future. Richard Lewis, MD, Sacramento, Calif.; Thomas Samuelson, MD, adjunct associate professor of ophthalmology, University of Minnesota, Minneapolis; and Rohit Varma, MD, professor and chair, University of Illinois at Chicago (UIC) Eye and Ear Infirmary, Department of Ophthalmology and Visual Sciences, and associate dean for strategic planning, UIC College of Medicine, discussed the AqueSys device, including concerns and approaches it takes in comparison to other glaucoma treatments. The device and approach Dr. Lewis said MIGS is helping to transform glaucoma surgery. The AqueSys device is part of this transformation, and it operates in the subconjunctival space. "It's the space that we've been using for close to 100 years, but we've never had a MIGS procedure to get access to it," Dr. Lewis said. This offers the advantage of a simpler and safer way of doing a well-recognized procedure. AT A GLANCE The AqueSys inserter "The AqueSys technology and approach is focused on using the gold standard mechanism of action that has been proven successful around the world for 50 plus years, which is subconjunctival outflow," Mr. Bache said. "But we reinvented the methodology in terms of how the procedure is done, so instead of being ab externo with a lot of surgery with an invasive nature on the outside of the eye, we deliver the implant in an ab interno procedure." He said this approach is easily adopted by both glaucoma and cataract surgeons. "In addition to that, the material that is used for the implant is a gelatin material that is crosslinked to be permanent, but it's soft, non-inflammatory, and tissue conforming," Mr. Bache said. "So those two aspects of a minimally invasive ab interno procedure and the gelatin material make this a highly attractive method for significantly lowering intraocular pressure to the levels that are needed by glaucoma patients but doing it in a safe, adoptable, and standardized manner." Mr. Bache said the AqueSys approach helps to bypass potential outflow obstructions by establishing a new pathway with the implant and procedure. "What makes us different is our mechanism of action from some of the other minimally invasive technologies," he said. There is still a lot of debate about where the outflow obstruction actually occurs in a glaucomatous eye, Mr. Bache said. It was believed in the past that the majority was just at the trabecular meshwork, but the thinking has evolved that the obstruction could be occurring further downstream as well, he said. A standardized procedure that bypasses all of the potential outflow obstructions is understandable and has been proven in glaucoma treatment for decades, Other devices Several other companies are also working on glaucoma implants at various stages of testing and approval. The AquaFlow Collagen Glaucoma Drainage Device by STAAR Surgical (Monrovia, Calif.) is designed to reduce intraocular pressure with a collagen implant. The device creates a path for excess fluid to reduce pressure. This method does not penetrate the chamber of the eye. The device is designed to be implanted in about 30 to 45 minutes, with minimal recovery time. The Alcon (Fort Worth, Texas) EX-PRESS Glaucoma Filtration Device works on a similar level to the AqueSys implant, said Dr. Varma. The device is small and implanted between the inner and outer region of the eye. The device helps to bypass the drainage system of the eye. • The AqueSys implant operates in the subconjunctival space, making it similar to trabeculectomy procedures and different from other MIGS approaches. • The gelatin implant has been approved in many countries, but has not yet gained FDA approval in the U.S. • The implant procedure does not currently use mitomycin. However, mitomycin is often thought to help in glaucoma procedures, although it can put patients at risk for complications as well. but AqueSys now allows it to be done in a minimally invasive way that is safe and effective for all stages of glaucoma. Dr. Varma said that the AqueSys implant is fairly simple and easy to insert. He also said that the drainage pathway is very much the same as that used in trabeculectomy procedures. "It's a well-known pathway for reducing eye pressure in patients with glaucoma." It also helps to bypass the trabecular meshwork by using the subconjunctival space. Dr. Samuelson agreed that the AqueSys implant most closely resembles a traditional surgery, like a trabeculectomy, but he said it addresses the problem in a more elegant way. "It's a completely novel approach," he said. "The AqueSys strategy is completely different than all the other things that are being developed right now." Dr. Samuelson said the one thing the implant has in common with other MIGS procedures is that these are done through a clear corneal incision, but he said the way it uses the subconjunctival space is unique. Other devices use Schlemm's canal or the suprachoroidal space. "It's not directly comparable to the other MIGS procedures because they're designed to enhance the eye's natural outflow," Dr. Samuelson said. "This is completely bypassing the eye's natural outflow system." Trials and approval Currently, the AqueSys glaucoma implant is awaiting approval from continued on page 40