Comparing iStent complications across four generations: a manufacturer and user facility device experience (MAUDE) database study

Abstract

Purpose: To report real-world intraoperative and early postoperative (< 3 months) complications of iStent surgery and analyze notable examples.

Patients and methods: The Manufacturer and User Facility Device Experience database was queried for "iStent" reports from January 2014 to March 2024. Late postoperative events, reports containing inadequate detail, and those from indirect sources (e.g., published literature, social media posts) were excluded. Adverse events were analyzed per device generation.

Results: A total of 808 reports were included, revealing 437, 377, 465, and 48 adverse events across the different iStent generations. The most common intraoperative events were malposition for iStent Trabecular Micro-Bypass, Inject, and Infinite (35%, 40%, 35%) and trocar damage for Inject W (34%). Surgeons and the manufacturer most frequently cited trocar bias as the cause of trocar damage. When the timing of trocar damage was specified, 66.7% occurred during deployment of the final stent of the series. Notably, device-derived foreign body contamination was exclusive to Inject W (11). The most common early postoperative event for all four generations was elevated intraocular pressure (IOP), occurring in 32%, 38%, 15%, and 15% of cases respectively. For the Infinite, hyphema was observed at a comparable proportion (15%).

Conclusion: Post-market data highlight distinct complication profiles across iStent generations, with malposition and elevated IOP as leading reported issues. Generation-specific trends, such as trocar damage in Inject W and Infinite, underscore the need for tailored surgical vigilance and further study.

Keywords: Device malfunction; Micro-Invasive glaucoma surgery (MIGS); Post-market surveillance; Surgical technique; Trocar damage.