PP031 iStent® For Open Angle Glaucoma: Standard Or Emerging Care?

Abstract

INTRODUCTION:

Increased intraocular pressure (IOP) in open angle glaucoma (OAG) may lead to optic nerve damage due to progressive obstruction of aqueous humor drainage. Among surgery options, trabecular micro-bypass stent (iStent®) was recently introduced. This Health Technology Assessment (HTA) aimed to assess the effectiveness and safety of iStent®, combined or not with cataract surgery, in patients with mild-to-moderate OAG.

METHODS:

A systematic review (SR) was performed from 2000 to August 2016. Studies reporting data at three months or more on IOP and hypotensive medication use following iStent® implant were eligible. Governmental databases on safety issues were reviewed. The project involved an interdisciplinary group of experts.

RESULTS:

Two HTA reports, one SR, four randomized controlled trials (RCTs) and nine observational studies (OSs) were included. Compared to cataract surgery alone, implantation of iStent®combined with cataract surgery was associated with a decrease in IOP at 12 months in RCTs (-1.37 mmHg; 95 percent Confidence Interval, CI: - 2.76 to .03 mmHg, p = .055). Results from RCTs and OSs on the effect of iStent® combined or not with cataract surgery suggest also a 12-month positive effect on IOP (mean reduction: 1.5 to 9.5 mmHg) and on mean number of medications (reduction: .3 to 2.0) compared to baseline. Scattered results were found on the proportion of patients who no longer use glaucoma medications. Small sample size, short duration of follow-up, and potential conflicts of interest were among studies limitations. The most common adverse events reported were posterior capsular opacification, decrease in visual acuity, and stent obstruction or malposition.

CONCLUSIONS:

Appraisal of the effectiveness and safety suggests that iStent® implantation combined to cataract surgery in mild-to-moderate OAG is an emerging practice. Uncertainties related to clinical benefits, safety and care organization need to be clarified before an introduction as a standard of medical practice.