Circumferential Schlemm’s Canal Surgery in Adult and Pediatric Glaucoma

Abstract

ABSTRACTPurpose: Although trabeculectomy, and to a less extent glaucoma drainage devices are currently the gold standard in glaucoma surgery, there is a rising interest in addressing the more physiological pathway of aqueous outflow through surgeries that target Schlemm’s canal (SC). These surgeries have the advantage of a lower risk of hypotony and bleb-related complications commonly associated with conventional glaucoma surgery.In this article we review new developments and the different techniques of circumferential angle surgery in adult and pediatric glaucoma, as well as procedures which target the canal circumferentially without incising it, such as canaloplasty and Visco360.Methods: A comprehensive literature search of various electronic databases was performed.Results: Angle surgery, namely goniotomy and trabeculotomy, have been well established as standard procedures in pediatric glaucoma, yet their results in the management of adult glaucoma have not been as promising. In recent years, ab-interno trabeculectomy using Trabectome and Kahook dual blade have yielded variable results in adult glaucoma. As growing evidence suggests that bigger extent incisions into SC result in increased lowering of intraocular pressure than conventional 120 to 180-degree incisions, several procedures have been developed to create a circumferential incision into SC. Circumferential SC incision using sutures, microcatheters, TRAB360 or the rigid probe trabeculotome, through an ab-interno or ab-externo approach, have yielded promising results in both adult and pediatric glaucoma by reducing the resistance to aqueous outflow through the inner wall of SC over 360 degrees of the angle.Conclusions: Various techniques of circumferential Schlemm’s canal surgery is effective in management of different adult and pediatric glaucomas. Further long-term comparative studies would be useful in evaluating safety and efficacy of these procedures