الفهرس | Only 14 pages are availabe for public view |
Abstract Summary Trabeculectomy has been for many years and still the most widely used filtering surgical procedure. However complications are commonly observed in this type of surgery such as hypotony, collapse of anterior chamber, cataract, hyphema, expulsive hemorrhage, choroidal hemorrhage and detachment and endophthalmitis. Nonpenetrating glaucoma surgeries have been developed in recent years, in order to improve the safety of conventional filtering procedures and decrease the incidence of complications occurring after it. Nonpenetrating glaucoma surgeries refer to drainage procedures that restore aqueous humor filtration through a natural membrane, the trabeculo-Descemet’s membrane without the penetration of anterior chamber. It targets the presumed site of pathology, namely Schlemm’s canal and the juxtacanalicular meshwork. Deep sclerectomy and viscocanalostomy are the most commonly used non-penetrating procedures. Canaloplasty is a relatively new nonperforating blebless technique for open-angle glaucoma, in which a microcatheter is inserted within Schlemm’s canal for the entire 360 degrees. All nonpenetrating glaucoma surgeries intend to achieve a progressive reduction of intraocular pressure, limit early postoperative hypotony, and eliminate the need for an iridectomy. As a result, they minimize some complications of trabeculectomy. Recently new class of procedures, termed micro-invasive glaucoma surgery (MIGS), has raised excitement within the glaucoma community by offering an alternative form of effective intraocular pressure reduction associated with lower medication burden and complication rates. Several new devices are currently being evaluated in clinical trials and all of them have the concept of using an alternative pathway for aqueous drainage, either Schlemm’s canal or Summary 83 the suprachoroidal space. Early data of the use of micro invasive glaucoma devices show great promise for the future of glaucoma surgery. Glaukos trabecular micro-bypass stent is an ab interno device that seeks to augment the conventional outflow pathway of aqueous humor by providing a direct communication between the anterior chamber and Schlemm’s canal. Express shunt facilitate aqueous outflow from the anterior chamber to a subconjunctival reservoir in a similar fashion as trabeculectomy, without removal of any sclera or iris tissue, requiring a smaller incision into the anterior chamber. The CyPass device is a suprachoroidal microshunt designed to create controlled aqueous outflow from the anterior chamber into the suprachoroidal space able to significantly lower the IOP and decrease the medication burden. The SOLX gold shunt is an ab externo device, designed to transmit aqueous from the anterior chamber to the suprachoroidal space and produce effective decrease intraocular pressure. Early results are promising. The Hydrus Microstent has been designed to bypass the trabecular meshwork and scaffold and dilate approximately one quadrant of Schlemm’s canal. It is currently in clinical trials. The Aquashunt is a suprachoroidal device. Results data are limited at this time |