Gold Micro-Shunt Implants Versus Ahmed Glaucoma Valve: Long-term Outcomes of a Prospective Randomized Clinical Trial

Purpose: To compare long-term outcomes of Ahmed glaucoma valve (AGV), 24 mu m Gold Micro-Shunt (GMS), and 48 mu m GMS implantation for treatment of refractory glaucoma. Patients and Methods: This was a 3-armed randomized interventional prospective clinical trial. Within an institutional setting, 29 adults (29 eyes) with refractory glaucoma [mean baseline intraocular pressure (IOP) >= 22 mm Hg on maximal medication, status post at least 1 failed trabeculectomy, defined visual field defect, and without recent glaucoma-related surgery] were randomly assigned to AGV, 24 mu m GMS, or 48 mu m GMS implantation. Exclusion criteria included uveitic, traumatic, or neovascular glaucoma. The 3 groups were comparatively evaluated preoperatively and 1, 2, 3, and 5 years postoperatively for IOP and numbers of glaucoma medications needed. Main outcome measures were implant survival rates. Results of the 24 and 48 mu m GMS groups were also compared separately. Results: In all groups the final IOP (in mm Hg) was significantly lower than the preoperative IOP (17.3 +/- 2.6 vs. 33.5 +/- 6.7, P = 0.004; 17.8 +/- 2.4 vs. 25.7 +/- 0.7, P = 0.0001; and 19.6 +/- 5.2 vs. 35.6 +/- 2.2, P = 0.0001 in the AGV, 24 mu m GMS, and 48 mu m GMS groups, respectively). Differences between initial and final mean numbers of medications were not significant. Cumulative probabilities of success at 5 years were 77.8%, 77.8%, and 72.7%, respectively. Conclusions: During long-term follow-up, success rates in the 2 GMS groups and the AGV group were similar. Likewise, IOP reduction and the need for continued glaucoma medical therapy remained high and were similar for all devices.