Clinical Investigation of New Glaucoma Procedures

Kateki Vinod; Steven J. Gedde


Curr Opin Ophthalmol. 2017;28(2):187-193. 

In This Article

Abstract and Introduction


Purpose of review This article reviews recent studies evaluating the efficacy and complication profiles of novel glaucoma procedures promoting aqueous outflow.

Recent findings Literature from the 2015 to 2016 review period includes abundant data regarding new and emerging glaucoma procedures. Notable findings from recent randomized clinical trials include titratability of intraocular pressure with multiple trabecular microbypass stents (iStent; Glaukos, Laguna Hills, California, USA) and greater reduction in intraocular pressure and medication usage following intracanalicular scaffolding (Hydrus Microstent; Ivantis Inc., Irvine, California, USA) combined with phacoemulsification vs. phacoemulsification alone. A supraciliary microstent (CyPass Micro-Stent; Transcend Medical, Inc., Menlo Park, California, USA) received approval from the Food and Drug Administration after a pivotal trial demonstrated its efficacy and safety. Early studies of investigational subconjunctival filtering devices (XEN Gel Stent; AqueSys, Inc., Aliso Viejo, California, USA and InnFocus MicroShunt; InnFocus Inc., Miami, Florida, USA) offer promising evidence, but late complications are as yet unknown.

Summary Newer glaucoma procedures targeting different aqueous outflow pathways have improved the safety profile of glaucoma surgery while preserving modest efficacy. Most can be combined with phacoemulsification, allowing for simultaneous treatment of comorbid cataract and glaucoma. Well-designed randomized clinical trials with extended follow-up remain necessary to evaluate the long-term efficacy and late complications of these novel procedures.


Open angle glaucoma (OAG) has traditionally been managed using a stepwise approach, beginning with medical and/or laser therapy and reserving incisional surgery for patients with progressive disease or intraocular pressure (IOP) elevation to a level at which progression is likely to occur. Postoperative complications associated with trabeculectomy and tube shunt surgery are well described and occur at a low but discernible rate.[1,2] The past decade has witnessed the emergence of new procedures designed to improve the safety profile of traditional glaucoma surgery (i.e., trabeculectomy and tube shunts) while preserving at least modest efficacy. Patients with milder disease who do not require very low IOP and may benefit from reduction in medical therapy are currently the best candidates for the newer surgeries. One advantage common to most of these novel surgical approaches is their ability to be combined with phacoemulsification cataract extraction, which is particularly important as the incidence of comorbid cataract and glaucoma increases in our aging population. Here we review the design, efficacy, and safety of new glaucoma procedures promoting aqueous outflow, organized by anatomical target [Table 1].