Clinical outcomes of the PAUL Glaucoma implant for neovascular glaucoma

In neovascular glaucoma (NVG), surgical interventions such as glaucoma drainage devices (GDD), may become necessary, especially when other therapies prove ineffective. The PAUL® Glaucoma Implant (PGI), with its refined, smaller drainage tube, presents a promising solution for lowering intraocular pressure (IOP) in such complex cases. This study aims to evaluate the PGI's effectiveness and safety in managing IOP in patients with NVG.

This study reviewed medical records of patients who underwent PGI surgery for NVG at the University Hospital Bonn between May 2021 and January 2024. Preoperative and follow-up data, including IOP, BCVA, visual field progression, and complications, were collected prospectively. Success was defined using four IOP-based criteria (≤ 21, ≤ 18, ≤ 15, and ≤ 12 mmHg) per World Glaucoma Association (WGA) guidelines (World Glaucoma Association et al. 2009). Outcomes were classified as complete (without medication) or qualified (with or without medication). Failure included hypotony-related complications, need for further surgery, or PGI explantation. The primary endpoint was success rate by IOP criteria; secondary endpoints included changes in IOP, BCVA, medication use, complications, and impact of Prolene stent removal.

The study analyzed 23 eyes from 22 patients undergoing PGI surgery, with the majority being male (60.9%) and Caucasian (95.7%), and with an average age of 65.2 years. Success rates were highest for IOP ≤ 21 mmHg (60%-80% at 12 months) and declined with stricter thresholds, with only 10% maintaining IOP ≤ 12 mmHg. Prior to surgery, the mean intraocular pressure (IOP) was 27.22 mmHg. Following the procedure, a substantial reduction was observed, with IOP decreasing to 12.95 mmHg at the 12-month follow-up-representing an average decrease of 53.1%.

The PGI demonstrates significant IOP reduction in NVG, with sustained success at higher IOP thresholds. However, maintaining very low IOP levels remains challenging.