Intraoperative predictors of success of iStent placement with cataract surgery.

Objective: To investigate and assess the intraoperative predictors for successful 1-year outcomes of iStent inject for patients with open angle glaucoma.

Design: Retrospective case series.

Participants: Patients who underwent combined iStent inject placement and cataract surgery between October 2018 and August 2022.

Methods: A priori predictors of interest included the number of stents placed, the number of clicks required to place them, stent spacing, intraoperative reflux of blood from the stent, and observed flow of aqueous through external vasculature. The primary outcome was the intraocular pressure (IOP) medication index.

Results: This study included 99 eyes of 57 patients. The mean preoperative IOP was 14.9 (±3.7) mm Hg, and mean number of drops were 1.7 (±0.7). The mean postoperative follow-up was 15.6 (±5.9) months. The mean postoperative IOP was 13.6 (±6.1) mm Hg and medication reduction was -1.5 (±4.2 mm Hg). Using the IOP medication index, 92.6% of eyes were categorized as having a successful procedure. Multivariate analysis showed that flow in both one (p = 0.030) and two (p = 0.034) stents were independent predictors of success after 1 year.

Conclusions: The IOP medication index showed a statistically significant association between flow from both 1 and 2 stents. Flow can be used as a predictor by surgeons to change patients' surgical plans intraoperatively and to monitor patients more closely postoperatively.