Abstract
Purpose:
To evaluate the results of the Ahmed glaucoma drainage device in eyes that had a failed trabeculectomy.
Methods:
This retrospective study evaluated 61 eyes (61 patients) with a failed trabeculectomy that underwent the implantation of an Ahmed glaucoma drainage device (model S2- n=29, model FP7-n=32) due to uncontrolled IOP under maximal medical therapy. Outcome measures included IOP, visual acuity, number of antiglaucoma medications, and complications. Success was defined as IOP < 21mmHg (criterion 1), or 20% reduction in IOP (criterion 2) with or without antiglaucoma medications. Persistent hypotony (IOP < 5 mmHg after 3 months of follow-up), loss of light perception, and re-intervention for IOP control were defined as failure.
Results:
Mean preoperative IOP and mean IOPs at 6 months, 12 months, 18 months, and 24 months were 21.93 + 6.32 mmHg (n=61), 14.15 + 4.33 mmHg (n=59), 13.21 + 4.44 mmHg (n=56), 12.21 + 3.37 mmHg (n=34), and 13.60 + 3.27 mmHg (n=25), respectively. Mean IOP reductions were statistically significant at all time intervals (p<0.001). Mean number of antiglaucoma medications preoperatively, at 6 months , 12 months, 18 months, and 24 months were 3.95 + 0.85 (n=61), 2.19 + 1.38 (n=59), 2.48 + 1.44 (n=56), 2.24 + 1.37 (n=34), and 2.40+ 1.32 (n=25), respectively. The reductions in the mean number of antiglaucoma medications were statistically significant at all time intervals (p<0.001). According to criterion 1, the Kaplan-Meier survival curve disclosed success rates of 75% at 12 and 24 months. According to criterion 2, the Kaplan-Meier survival curve disclosed success rates of 57% at 12 months and 55% at 24 months. The most frequent complications were shallow anterior chamber (16.4%), choroidal detachment (4.9%), and hypertensive phase (4.9%).
Conclusions:
Ahmed glaucoma device implantation may effectively reduce IOP in eyes with uncontrolled glaucoma with a failed trabeculectomy, and is associated with relatively few complications.