Outcomes of intraluminal ripcord removal from Paul glaucoma implants

BACKGROUND/AIMS: To investigate the efficacy and safety of intraluminal ripcord suture removal (ROS) from the Paul glaucoma implant (PGI). METHODS: A retrospective cohort study involving all PGI ripcord removal cases at a single centre between 1 January 2018 and 1 November 2023. The primary outcome was defined as a ≥20% reduction in intraocular pressure (IOP), or a decrease in IOP-lowering medications, at 3 months post-ROS. RESULTS: 145 eyes of 131 patients were included. The mean interval between PGI implantation and ROS was 181.9±131.4 days. 70.3% of eyes met the primary endpoint of success, with second tubes and infero-nasal tube placement significantly associated with reduced success (p<0.05). Compared with the pre-ROS mean IOP (19.5±6.7 mm Hg), the post-ROS IOPs at 1 week, 1 and 3 months were significantly reduced to 12.7±7.4 mm Hg, 15.3±6.1 mm Hg and 13.7±5.3 mm Hg, respectively (p<0.0001). Similarly, the number of IOP-lowering medications was significantly reduced to 0.44±0.97, 0.75±1.18 and 1.12±1.30, respectively (p<0.005). Post-ROS complications included clinically significant hypotony (n=10, 6.9%), of which 6 eyes (4.1%) required surgical ripcord re-insertion, tube shunt occlusion (n=2, 1.4%) and post-ROS uveitis (n=1, 0.69%). We found no predictive factors for post-ROS hypotony, including the time of ROS since PGI surgery. CONCLUSIONS: ROS from PGI resulted in at least 20% IOP or medication reduction in over 70% of eyes. Second and inferonasal tubes had reduced success. Clinical hypotony is the most common complication, without association with the time of stent removal since PGI implantation.