# From first generation to the next: evolution and research trends in iStent technology

## TL;DR

The iStent is a minimally invasive glaucoma surgery device that has evolved since 2012 to better reduce eye pressure with few complications.

## Contribution

The paper reviews the evolution and clinical outcomes of successive iStent device generations in glaucoma treatment.

## Key findings

- Long-term iStent use shows durable intraocular pressure and medication reduction with minimal complications.
- iStent effectiveness extends beyond mild-to-moderate open-angle glaucoma, including cases with cataract surgery.
- Combination MIGS with iStent may enhance efficacy without compromising safety.

## Abstract

The iStent series constitutes a range of trabecular bypass minimally invasive glaucoma surgery (MIGS) devices, which offers intraocular pressure (IOP) reduction with favourable safety profiles, in patients with open-angle glaucoma (OAG). Having undergone significant evolution since its initial US FDA-approval in 2012, successive generations address previous limitations, while enhancing IOP-lowering efficacy through device and delivery system design iterations. Longer-term and real-world iStent data demonstrate the durability of IOP- and medication-lowering outcomes with minimal complications, while preliminary studies across a wider spectrum of glaucoma subtypes and severities provide limited evidence of successful outcomes beyond mild-to-moderate OAG, both with and without concomitant cataract surgery. Aqueous humour outflow assessment and novel intra-operative techniques may further facilitate more accurate and effective iStent positioning. Despite typically higher upfront costs, results from both cost-effectiveness and patient-reported outcome studies are encouraging. Combination MIGS with the iStent, leveraging on the multiple mechanisms of actions of various procedures, may provide greater IOP-lowering efficacy without compromising safety. With expanding clinical data and progressive enhancements, iStent technology is likely to remain a key component of the evolving MIGS landscape.