Clinical outcomes of the PAUL glaucoma implant in primary open-angle and pseudoexfoliative glaucoma eyes after failed glaucoma surgeries.

Purpose: This study assesses the PAUL® glaucoma implant (PGI) in primary open angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG) after failed glaucoma surgery. Given PEXG's more aggressive nature, limited research exists on PGI outcomes in this subgroup. This study aims to compare PGI's efficacy and safety in both conditions.

Methods: A retrospective cohort study including patients undergoing PGI surgery at the University Eye Hospital Bonn, Germany, from April 2021 to January 2024. Patients were enrolled in a database at the time of surgery, with follow-up data collected at each visit. Success was defined according to four criteria, using intra-ocular pressure (IOP) thresholds of ≤21 mmHg (Criterion A), ≤18 mmHg (Criterion B), ≤15 mmHg (Criterion C) and ≤12 mmHg (Criterion D).

Results: Forty-eight eyes of 48 patients were included. Qualified and complete success rates (95% CI) were 60.4% (45.8-72.9) and 93.8% (87.5-100) for Criterion A, 60.4% (45.8-72.9) and 85.4% (75-95.8) for Criterion B, 43.8% (29.2-56.3) and 58.3% (43.8-72.9) for Criterion C and 33.3% (20.8-47.9) and 35.4% (22.9-50) for Criterion D. Mean IOP decreased from 23.52 mmHg (7-45) to 11.65 mmHg (3-20 mmHg) with a mean reduction of 43.55% (0-82%) at 12 months, with a reduction in IOP-lowering agents from 3.13 (1-5) to 0.44 (0-3). Postoperative complications occurred in 33.3% of cases. Approximately 6.3% required additional glaucoma procedures, leading to surgical failure. Regarding primary outcomes, no significant differences were observed for qualified or complete success rates between POAG and PEXG. Both groups had similar preoperative IOP and experienced significant postoperative reduction, with no statistically significant differences in IOP, medication use, visual outcomes, complications, revision rates or surgical failure at 12 months.

Conclusions: In conclusion, the PGI demonstrated significant IOP reduction and decreased need for medication in both POAG and PEXG patients, with no major differences between the two groups at 12 months. The implant's overall safety and efficacy make it a viable surgical option for both conditions. Further studies are needed to assess long-term outcomes and refine patient selection criteria.