Two-year efficacy and safety outcomes of the Paul Glaucoma Implant compared to the Ahmed Glaucoma Valve

Abstract

PURPOSE: To compare efficacy and safety profiles of the Paul Glaucoma Implant (PGI) and Ahmed Glaucoma Valve (AGV) in the treatment of adults with glaucoma over a 2-year of follow-up period. METHODS: This retrospective, single-center, comparative study included adult patients who underwent standalone PGI or AGV surgery at the University Medical Center Mainz. Twenty-two consecutive patients treated with the PGI were compared with a historical cohort of 17 eyes that underwent AGV implantation prior to the introduction of the PGI, all with a minimum follow-up of 24 months. The primary outcome measures were changes in intraocular pressure (IOP) and the number of antiglaucoma medications at two years postoperatively. Secondary outcome measures included complete and qualified success rates, failure rates, best-corrected visual acuity (logMAR), and the incidence of adverse events. RESULTS: At 24 months of follow-up, median intraocular pressure (IOP) decreased similarly in both groups, from 28.0 mmHg (IQR 16) to 12.0 mmHg (IQR 9) in the AGV group and from 32.5 mmHg (IQR 11) to 14.0 mmHg (IQR 4) in the PGI group. Overall qualified success rates were comparable between groups for target IOP criteria of ≤ 21 mmHg with ≥ 25% reduction and ≤ 15 mmHg with ≥ 40% reduction. However, the PGI group demonstrated higher success rates for the target IOP of ≤ 18 mmHg with ≥ 30% reduction. The AGV group exhibited a higher incidence of early postoperative complications and bleb encapsulation. CONCLUSION: Both PGI and AGV were safe and effective in reducing intraocular pressure over 2 years. PGI was associated with lower device obstruction rates and a higher likelihood of achieving an intraocular pressure of ≤ 18 mmHg at 2 years.