Spotlight on Schlemm’s Canal MicroStent Injection in Patients with Glaucoma

Abstract

Minimally invasive glaucoma surgery (MIGS) has revolutionized glaucoma care with its favorable safety profile and ability to delay or minimize the need for traditional, bleb-based procedures. Microstent device implantation is a type of angle-based MIGS, which reduces intraocular pressure (IOP) through bypass of the juxtacanalicular trabecular meshwork (TM) and facilitation of aqueous outflow into the Schlemm’s canal. Although there are limited microstent devices on the market, multiple studies have evaluated the safety and efficacy of iStent^® (Glaukos Corp.), iStent Inject^® (Glaukos Corp.), and Hydrus^® Microstent (Alcon) in the treatment of mild-to-moderate open-angle glaucoma, with and without concurrent phacoemulsification. This review attempts to provide a comprehensive evaluation of injectable angle-based microstent MIGS devices in the treatment of glaucoma.

Keywords:

• microstent injection
• Schlemm’s canal
• Hydrus microstent
• iStent
• glaucoma
• aqueous outflow

Literature Search

A literature search of PUBMED for all literature from 1 January 1960 to 1 April 2023 was performed. The search was carried out with a combination of the following key terms: “MicroStent Injection,” “Schlemm’s canal inject,” “Hydrus MicroStent,” “iStent,” and “minimally invasive glaucoma surgery.” All accessible article types (clinical studies, randomized controlled trials, review articles, case series, and case reports) were included. A total of 546 articles were found. All articles and their references were scrutinized, and 46 articles were deemed relevant for the purpose of this review.

Consent for Publication

No personal identifying information is contained within this review article. All images have been deidentified.

Acknowledgments

The authors acknowledge Bryan Ang, FRCOphth for his intraoperative photos of the iStent inject (Figure 1A), iStent inject W (Figure 1B), and Hydrus Microstent (Figure 1C).

Author Contributions

All authors made a significant contribution to the work reported (conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas); took part in drafting, revising, or critically reviewing this article; gave final approval of the version to be published and agreed on the journal the article was submitted to; and agree to be accountable for all aspects of the work.

Disclosure

Dr Bryan Ang is a consultant for and reports research and speaker’s honorariums from Glaukos Corporation and Alcon, Inc., outside the submitted work. The authors report no other conflicts of interest in this work.

Additional information

Funding

No funding or grant support was obtained for this study.