Treatment Outcomes Using the PAUL Glaucoma Implant to Control Intraocular Pressure in Eyes with Refractory Glaucoma

Abstract

Purpose: To investigate efficacy 1 year after implantation of a novel glaucoma tube shunt, the PAUL Glaucoma Implant (PGI; Advanced Ophthalmic Innovations, Singapore, Republic of Singapore), in the treatment of eyes with refractory glaucoma.

Design: Clinical trial.

Participants: Glaucoma patients who are recalcitrant to maximum tolerated medical therapy and require tube shunt surgery.

Methods: Interventional cohort study involving consecutive PGIs implanted at 6 international centers between December 1, 2017, and December 1, 2018. All the participants were followed up for 1 year after surgery.

Main outcome measures: The primary outcome measure was failure, defined prospectively as intraocular pressure (IOP) of more than 21 mmHg or less than 20% reduction from the preoperative baseline on 2 consecutive visits, 3 months or more after surgery; persistent late hypotony, defined as IOP of less than 6 mmHg on 2 consecutive visits after 3 months; additional glaucoma surgery; loss of light perception vision; or removal of the implant for any reason.

Results: Of 82 patients enrolled, 74 (74 eyes) completed 12 months of follow-up. The mean age ± standard deviation at enrollment was 62.3±14.7 years, 73.0% were men, and 36.5% had secondary glaucoma. One year after surgery, 4 patients (5.4%) fulfilled the surgical criteria for failure, 68.9% (51/74 eyes) were deemed complete successes, and 93.2% (69/74 eyes) were considered qualified successes. Compared with the medicated preoperative IOP (23.1±8.2 mmHg), the postoperative IOPs at 6 and 12 months were 13.8±4.0 mmHg and 13.2±3.3 mmHg, respectively (P < 0.001). The mean number of IOP-lowering drugs used before surgery and after 12 months of follow-up were 3.3±0.9 and 0.3±0.6, respectively (P < 0.001). Significant postoperative complications included self-limiting shallow anterior chamber (n = 11; 14.9%), hypotony requiring intervention (n = 7; 9.5%), tube shunt occlusion (n = 5; 6.8%), tube exposure (n = 3; 4.1%), and endophthalmitis with resultant loss of vision (n = 1; 1.4%).

Conclusions: The PGI demonstrated comparable efficacy with other currently available implants, with almost three quarters of the enrolled patients with refractory glaucoma achieving complete surgical success after 1 year of follow-up.