Purpose:To investigate the efficacy of intraocular pressure (IOP) control and medication use over time after trabeculectomy (TRBC) and Ex-PRESS shunt implantation in primary-open-angle-glaucoma (POAG) patients.Design:Retrospective case series.Patients and methods:A total of 33 unilateral POAG patients were enrolled, and 17 patients received traditional TRBC and 16 patients received Ex-PRESS device implantation. Data on IOP, reduction of antiglaucoma medication, and major complications were collected and analyzed after 12 months of follow up.Results:After 12 months of follow up, both groups showed good IOP control. The mean preoperative IOP decreased from 38.5 (±6.9) to 18.2 (±11) mmHg after TRBC, and from 38.5 (±9.1) to 19.53 (±12.36) mmHg after Ex-PRESS implantation (both p < 0.05). The mean number of antiglaucoma medications prescribed at the last follow up decreased from 3.2 (±0.5) preoperatively to 1.2 (±1.4) after TRBC versus 3.3 (±0.7) preoperatively to 1 (±0.9) after Ex-PRESS implantation (both p < 0.05). Complete success rate (defined as no medication after surgery with IOP >5 and <18 mmHg) and qualified success rate (defined as with or without medication after surgery with IOP >5 and <18 mmHg) were similar (47% vs. 43% and 76.47% vs. 75%) between the two groups without statistical difference (p > 0.05). However, postoperative hypotony rate was more frequent after Ex-PRESS (37.5%) than after TRBC (17.64%).Discussion:TRBC and Ex-PRESS implantation provided similar IOP control and reduction of postoperative medication with low incidence of postoperative complications at intermediate-term follow up. However, the Ex-PRESS implantation device may last longer but with extra costs. It is up to the surgeon to decide which procedure to use according to the patient's situation and economic circumstances.