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

Background: This study compared the efficacy of the EX-PRESS (R) 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.