Comparison of Ex-PRESS P-200 mini-shunt implantation and standard trabeculectomy for open-angle glaucoma: four-year follow-up

INTRODUCTION: The study aimed to evaluate the efficacy and safety in 4-year follow-up of Ex-PRESS P-200 mini-shunt implantation versus standard trabeculectomy. MATERIAL AND METHODS: A single-center retrospective study on patients diagnosed with open-angle glaucoma with failed medical treatment and who underwent Ex-PRESS device implantation or standard trabeculectomy was conducted. Seventy-three eyes were included in the analysis, 33 with Ex-PRESS P-200 implantation and 40 with standard trabeculectomy. RESULTS: Significant decreases in the intraocular pressure (IOP) were observed after surgery and at all follow-ups in both groups (p < 0.001) with no significant difference between the two groups (p > 0.40). No significant differences with regard to post-operative medications were observed (p > 0.10). Excepting the 3-year follow-up, when just a borderline significant difference regarding the visual acuity between the Ex-PRESS and standard trabeculectomy group was observed (p = 0.0504), the Ex-PRESS groups showed significantly better visual acuity at 6 weeks (p = 0.0324), 1 year (p = 0.0168), 2 years (p = 0.0162), and 4 years (p = 0.0111). Hypotony occurred more frequently among the Ex-PRESS group, while cataract occurred more frequently among those with standard trabeculectomy, without significant differences between groups (p > 0.09). No difference in hazard of failure was observed between interventions (HR = 0.72, p = 0.523). CONCLUSIONS: Both procedures provided good control of IOP and decreased the number of postoperative medications. The advantage of the Ex-PRESS shunt is the better visual acuity, but its main limitation is the cost.