Purpose: To evaluate the efficacy and safety of the Ahmed glaucoma valve in patients with refractory glaucoma.
Methods: In 142 eyes of 136 patients with uncontrolled glaucoma despite topical and/or systemic medical treatment, the Ahmed valve implant (New York Medical Inc. Rancho Cacamonga, CA) was placed for IOP control, during the last 5 years in the University Eye Clinic of Athens. The type of glaucoma was neovascular in 74 eyes, pseudophakic or aphakic in 19 eyes and failure of previous antiglaucomatous operations (two or more) in 49 eyes.
Results: Follow-up time ranged from 18 to 72 months with a mean follow-up of 38.6 months. Preoperative IOP decreased from 31.6 10.4 mmHg to 18,3 5.4 mmHg (only topical treatment) at the last examination. Comparison of preoperative IOP values using ANOVA demonstrated statistically significant difference (p < 0.001). Total success rate was 84.5% the first 6 months, 76.76% at 12 months and 51.4% at the last examination (18 to 72 months after implantation). Success rate was 25,7% in neovascular glaucoma, 63,2% in aphakic glaucoma and 73,8% in previous failed trabeculectomies. Complications associated with the use of the valve were: serous choroidal detachment 14,78%; blockage of the tube 2,81%; malposition of the tube 4,92%; suprachoroidal hemorrhage 2,11%; cataract progression 47,96% (59/123 phakic eyes); shallow anterior chamber 9,85%; hyphema 28,16%.
Conclusions: Although the success of the Ahmed valve implant is similar to that reported for other drainage devices, the complications associated with overfiltration in the immediate postoperative period appear to be less frequent than with other glaucoma valved drainage devices.