Five-year extension of a clinical trial comparing the EX-PRESS glaucoma filtration device and trabeculectomy in primary open-angle glaucoma

Abstract

Background: This study compared the efficacy of the EX-PRESS(®) glaucoma filtration device and trabeculectomy in primary open-angle glaucoma up to five years after surgery.

Methods: Patients from a previously reported randomized, open-label, parallel-arm clinical trial in which 78 patients received either the EX-PRESS glaucoma filtration device or underwent a trabeculectomy were followed for up to an additional four years (five total) beyond the original study (39 eyes per treatment group). Risk-benefit data were obtained for up to five years after glaucoma surgery. Outcome variables were intraocular pressures and intraocular pressure medications. Complete success was denoted by intraocular pressure values ≤ 18 mmHg without medication.

Results: The EX-PRESS glaucoma filtration device controlled intraocular pressure more effectively without medication for more patients from year 1 (86.8% versus 61.5%, P = 0.01) to year 3 (66.7% versus 41.0%, P = 0.02) than trabeculectomy. At year 1, only 12.8% of patients required intraocular pressure medication after EX-PRESS implantation, compared with 35.9% after trabeculectomy. The proportions became closer at year 5 (41% versus 53.9%). The responder rate was higher with EX-PRESS and time to failure was longer. In addition, surgical interventions for complications were fewer after EX-PRESS implantation.

Conclusion: This five-year analysis confirmed and extended the results reported after one year. Compared with trabeculectomy, EX-PRESS provided better intraocular pressure control in the first three years, and patients required fewer intraocular pressure medications and fewer surgical interventions during the five-year study period. For patients with primary open-angle glaucoma, the EX-PRESS glaucoma filtration device, implanted under a superficial scleral flap, produced significantly higher success rates than trabeculectomy. EX-PRESS is an effective device for long-term treatment of primary open-angle glaucoma.

Keywords: glaucoma filtration device; intraocular pressure; medication; primary open-angle glaucoma; trabeculectomy.

Figure 1

Survival curves comparing Ex-PRESS implants with trabeculectomy. A) Kaplan–Meier life table curves of complete success (IOP ≤ 18 mmHg): no IOP medication or subsequent glaucoma surgery (log-rank, p = 0.0049). B) Kaplan–Meier life table curves of partial success (IOP ≤ 18 mmHg), i.e. including IOP medication: no subsequent glaucoma surgery (log-rank, p = 0.0085). C) Kaplan–Meier life table curves for marginal success (IOP ≤ 18 mmHg) incorporating IOP medication and subsequent glaucoma surgery (log-rank, p = 0.18). D) Kaplan–Meier life table curves of complete success (IOP ≤ 15 mmHg): no IOP medication or subsequent glaucoma surgery (log-rank, p = 0.0014). E) Kaplan–Meier life table curves of partial success (IOP ≤ 15 mmHg) i.e. including IOP medication: no subsequent glaucoma surgery (log-rank, p = 0.0026). F) Kaplan–Meier life table curves of partial success (IOP ≤ 15 mmHg) i.e. including IOP medication: no subsequent glaucoma surgery (log-rank, p = 0.0026).