Microinvasive glaucoma surgery: an evidence-based assessment

Abstract

Introduction The advent of Microinvasive Glaucoma Surgery (MIGS) offers a novel approach in the treatment of glaucoma with the number of procedures developing at an exciting pace. Areas Covered MIGS procedures aim to lower intraocular pressure (IOP) via four mechanisms: (1) increasing trabecular outflow, (2) increasing outflow via suprachoroidal shunts, (3) reducing aqueous production, and (4) subconjunctival filtration. A comprehensive search for published studies for each Microinvasive Glaucoma Surgery (MIGS) device or procedure was undertaken using the electronic database PubMed. Search terms included ‘minimally invasive glaucoma surgery’, ‘microincisional glaucoma surgery’, and ‘microinvasive glaucoma surgery’. A manual search for each device or procedure was also performed. After review, randomized control trials and prospective studies were preferentially included. Expert Opinion These procedures offer several benefits: an improved safety profile allowing for intervention in earlier stages of glaucoma, combination with cataract surgery, and decreased dependence on patient compliance with topical agents. Established MIGS procedures have proven efficacy and more recent devices and procedures show promising results. Despite this, further study is needed to assess the long term IOP-lowering effectiveness of these procedures. Particularly, rigorous study with more randomized control trials and head-to-head comparisons would allow for better informed clinical and surgical decision-making. MIGS offers new solutions for glaucoma treatment.

Microinvasive Glaucoma Surgery: An Evidence-Based Review

“…The ab interno trabeculectomy (AIT) instrument was FDA-approved in 2004 and started being used in 2006 to treat OAG in the US. 8,9 The Trabectome uses electrocautery to remove a strip of the trabecular meshwork, generally over 90-120 degrees. The below studies are summarized in Table 1.…”

American Glaucoma Society Position Paper: Microinvasive Glaucoma Surgery

“…Canal-based MIGS lower IOP by improving outflow through the patient's natural drainage system, instead of creating a bleb (a subconjunctival reservoir from which aqueous humor can slowly egress, and thereby lower IOP) to capture the aqueous. 20 This considerably enhances the safety profile and limits discomfort, which can be an issue with traditional glaucoma procedures. Patients who are deemed not to be good candidates for canal-based MIGS still may be candidates for subconjunctival MIGS, a less invasive form of classic filtration surgery that uses microstents to create a bleb.…”

“…Patients who are deemed not to be good candidates for canal-based MIGS still may be candidates for subconjunctival MIGS, a less invasive form of classic filtration surgery that uses microstents to create a bleb. 20,21 Other potential advantages of MIGS over traditional glaucoma procedures include faster recovery, less impact on leisure activities (such as swimming), and reduced risk of damaging other structures in the eye that can necessitate additional ocular surgeries. Although many patients with different types and severities of glaucoma can benefit from MIGS, some patients clearly fare better with traditional glaucoma filtration surgery, so it is important to have all of these procedures available to allow the surgeon and patient together to decide which intervention is most appropriate.…”

Precision medicine to prevent glaucoma-related blindness

“…The intent of glaucoma surgery is to achieve low IOP with minimal IOP fluctuation and with minimal risk of complications, minimal impact on quality of life, and decrease medication burden. Various microinvasive glaucoma surgeries (MIGS) (20)(21)(22) have been introduced, but the long-term efficacy and cost-effectiveness of MIGS compared to trabeculectomy remain to be determined. The mechanisms for MIGS include targeting Schlemm's canal (SC) to increase aqueous humor outflow into aqueous veins, increase uveoscleral outflow, or create a small fistula to bypass the angle and divert aqueous humor into the subconjunctival space.…”