Ex-PRESS implantation versus trabeculectomy for long-term maintenance of low intraocular pressure in patients with open angle glaucoma

Purpose To compare the efficacy of Ex-PRESS implantation to trabeculectomy with mitomycin C, for maintaining low target intraocular pressure (IOP) in patients with open angle glaucoma. Materials and Methods Patients were randomly assigned to receive Ex-PRESS implantation or trabeculectomy. Patients with IOP ≥ 15 mmHg were included in this study. Surgical success was defined according to three target mean IOP ranges (5 mmHg ≤ IOP ≤18 mmHg [criterion A], 5 mmHg ≤ IOP ≤15 mmHg [criterion B], and 5 mmHg ≤ IOP ≤12 mmHg [criterion C]) representing reductions of at least 20% below baseline on two consecutive follow-up visits 3 months post surgery. Results A total of 73 patients, including 30 in the Ex-PRESS implantation group and 43 in the trabeculectomy group, were included in the study. The baseline IOP was 20.4 ± 4.9 mmHg in the Ex-PRESS implantation group and 21.9 ± 7.9 mmHg in the trabeculectomy group. There were no significant differences in baseline ocular or demographic characteristics between the two groups. There was no statistical difference in IOP every 6 months. After the 3-year follow-up, success rates were A) 60.0% and 60.2%, B) 45.7% and 58.1%, and C) 31.5% and 40.5% for the Ex-PRESS implantation and trabeculectomy groups, respectively. A greater number of glaucoma medications before surgery was associated with a higher failure rate in the trabeculectomy group but not the Ex-PRESS implantation group. Conclusions Both procedures resulted in similar IOP reductions and success rates for low target IOP. The number of preoperative glaucoma medications was a risk factor for trabeculectomy failure.