Three-Year Outcomes of the Paul Glaucoma Implant for Treatment of Glaucoma

Abstract

Prcis: In our case series, the 3-year failure for Paul Glaucoma Implant (PGI) implantation was 14.6%. At 3 years postoperatively, there was a significant reduction in mean intraocular pressure (IOP) and the number of glaucoma medications used.

Objective: To determine the 3-year efficacy and safety of the PGI, a novel glaucoma tube shunt in patients with glaucoma.

Methods: Retrospective review of all patients who had undergone PGI implantation in a single tertiary institution in Singapore between May 1, 2017 and January 1, 2022. Data were extracted from electronic health records (Computerized Patient Support System 2 and Epic). The primary outcome measure was failure, defined as IOP >18 mm Hg or <6 mm Hg on 2 consecutive visits after 3 months, reoperation for IOP-related indication, explantation of implant, or loss of light perception vision. Complete success was defined as the absence of failure without medications at 36 months, and qualified success similarly, but with medications. Postoperative mean IOP, mean number of IOP-lowering medications used, and visual acuity were also assessed.

Results: Forty-eight eyes in 48 patients were identified. Thirty-one patients (64.6%) had primary open angle and angle closure glaucoma, and 18 (37.5%) had previous existing tube implants or trabeculectomy. At 3 years postoperatively, 7 cases (14.6%) fulfilled the criteria for failure and 36 (75%) met the criteria for complete success. The mean IOP at 36 months was 14.9 ± 4.11 mm Hg, from the mean preoperative IOP of 20.6 ± 6.13 mm Hg ( P < 0.001). The mean number of IOP-lowering medications used was reduced from 3.13 ± 0.959 preoperatively to 0.167 ± 0.476 at 36 months ( P < 0.001). The most common postoperative complication was hypotony (n = 17, 35.4%), of which the majority were self-limiting, followed by hyphema (n = 5, 10.4%) and tube exposure (n = 4, 8.3%).

Conclusion: The PGI demonstrated sustained IOP reduction and a reduction of medication burden at 3 years postoperatively.

FIGURE 1

Cases lost to follow-up over a 3-year postoperative period.

FIGURE 2

Kaplan Meier Survival Curve over 3 years postoperatively.

FIGURE 3

Line graph showing intraocular pressure (IOP) trend over duration of follow-up, compared with highest preoperative IOP and mean preoperative IOP. Error bars indicate 95% CIs.

FIGURE 4

Line graph showing a trend of IOP-lowering medication use over the duration of follow-up, compared with preoperatively. Error bars indicate 95% CIs.