Utility of Collagen Matrix Insertion during Ahmed Valve Implantation with Adjunctive Mitomycin-C: Outcomes at One-year

Purpose: To compare the surgical outcomes of adjunctive mitomycin-C (MMC) Ahmed valve implantation with and without collagen matrix insertion. Methods: We retrospectively reviewed 108 eyes of 108 patients who underwent Ahmed valve implant surgery with adjunctive MMC. Collagen matrix insertion/Ahmed valve implant surgery (CM-AGV) was performed on 55 eyes, while conventional Ahmed valve implant surgery (AGV) was performed on 53 eyes. We defined surgical failure as an intraocular pressure (IOP) > 18 mmHg or <5 mmHg on two or more consecutive visits, regardless of medication status. Results: After surgery, the IOP and number of topical medications required fell significantly (compared with the preoperative period) in both groups (both p < 0.001); these findings did not significantly differ between groups. The cumulative surgical success rates at 1 year did not significantly differ between groups (78.2% vs. 79.2%, p = 0.54). The only risk factor significantly associated with surgical failure was a postoperative hypertensive phase. Anterior chamber (compared with sulcus) tube placement was significantly associated with visual acuity loss at 1 year postoperatively, but this did not significantly differ between groups. Conclusions: At the 1-year follow-up after Ahmed implant surgery with adjunctive MMC, the success rates of surgery with and without collagen matrix insertion were similar.