Surgical Outcomes of a Second Ahmed Glaucoma Valve Implant for the Treatment of Refractory Glaucoma.

PReCIS:: In this article we concluded that an additional AGV implantation after the failure of an initial AGV, even with the addition of glaucoma medications, may be a good surgical treatment option for refractory glaucoma. PURPOSE To evaluate the surgical outcomes of a second Ahmed glaucoma valve (AGV) implant in Hispanic patients with refractory glaucoma. MATERIALS & METHODS The medical records of patients who underwent a second AGV implant were reviewed retrospectively. Clinical outcome measures including intraocular pressure (IOP), visual acuity, and glaucoma medication use were collected from the preoperative visit and all follow-up visits up to 18 months after surgery. Failure was defined as one of the following: loss of light perception, sustained IOP >21▒mmHg or <6▒mmHg, an IOP reduction of <20% from baseline, need for additional glaucoma surgery, including needling revision with sub-conjunctival adjuvant therapy, or valve extrusion. RESULTS A total of 48 patients were included. In all cases, a S-2 model was implanted in the supero-nasal quadrant. Mean preoperative IOP was 24.3±7.9▒mmHg and was significantly reduced to 13.9±4.8 at 6 months (P=<0.05), 15.4±7.2 at 12 months (P=<0.05), and 12.9±2.0 at 18 months (P=<0.05). Mean glaucoma medications were reduced from 2.8±1.1 preoperatively to 1.9±1.2 at 6 months (P: <0.05), 2.4±1.2 at 12 months, and 2.2±1.1 at 18 months; however, the difference was no longer statistically significant after 6 months, and the success rate was 60% at the mean for survival time of 15 months (13.7-16.5). CONCLUSION The findings of this study demonstrate that a second AGV can achieve a significant reduction in IOP for up to 18 months postoperatively.