Evaluation of success after second Ahmed glaucoma valve implantation

Purpose:To evaluate the outcome of the second Ahmed glaucoma valve (AGV) surgery in eyes with failed previous AGV surgery.Design:Retrospective case series.Results:The average age of the patients was 32.7 years (range 4–65), and the mean duration of follow-up was 21.4 months (range 6–96). Preoperatively, the mean IOP was 26.94 mmHg (standard deviation [SD] 7.03), and the patients were using 2.8 glaucoma medications on average (SD 0.9). The mean IOP decreased significantly to 13.28 mmHg (SD 3.59) at the last postoperative visit (P = 0.00) while the patients needed even fewer glaucoma medications on average (1.4 ± 1.1, P = 0.00). Surgical success of second glaucoma drainage devices (Kaplan–Meier analysis), according to criterion 1, at 6, 12, 18, and 42 months was 94%, 85%, 80%, and 53% respectively, and according to criterion 2, was 94%, 85%, 75%, and 45%, respectively.Conclusion:Repeated AGV implantation seems to be a safe modality of treatment with acceptable success rate in cases with failed previous AGV surgery.