The Factors Associated with the Success of Ahmed Glaucoma Valve Implantation

ABSTRACT

PURPOSE: To evaluate the factors associated with the success of Ahmed glaucoma valve implantation in refractory glaucoma. METHODS: The medical records of 45 eyes of 45 patients that underwent Ahmed implant surgery for the treatment of refractory glaucoma were reviewed retrospectively. The success criterion was a stable postoperative intraocular pressure (IOP) between 6 and 21 mmHg with or without antiglaucoma medications during the study period. Failure was defined as an abnormal IOP outside of the above range on two consecutive visits, and cases that needed additional surgery to control IOP or to treat devastating surgical complications. We compared the differences in various clinical factors before surgery between the success and failure groups. RESULTS: The Kaplan-Meier cumulative success rate was 71.1% at 12 months. Among the various clinical factors age, gender, right or left eye, phakia or pseudophakia, systemic disease such as diabetes and hypertension, preoperative IOP, preoperative number of antiglaucoma medications, and the number of previous glaucoma or other ocular surgeries were not significantly different between the success and failure groups. Implantation at the superotemporal site and steroid non-responsders of the fellow eye showed a significantly greater success rate than the superonasal site and steroid responders, respectively, after Ahmed glaucoma valve implantation. CONCLUSIONS: The efficacy of lowering the IOP of an Ahmed glaucoma valve would be expected to be greater if the patient is a steroid non-responder. Given the same conditions in the superotemporal and superonasal areas, implanting the Ahmed glaucoma valve in the superotemporal quadrant showed an ito increased success rate.