A prospective comparative study on neovascular glaucoma and non-neovascular refractory glaucoma following Ahmed glaucoma valve implantation

BackgroundNeovascular glaucoma is a refractory disease, and difficult to manage. The aim of this study was to evaluate the clinical outcomes of Ahmed glaucoma valve implantation (AGVI) in neovascular glaucoma (NVG) and non-NVG patients.MethodsThis prospective, non-randomized study included 55 eyes of 55 patients with refractory glaucoma; 27 had NVG (NVG group) and 28 had non-NVG (non-NVG group). All of the patients underwent AGVI. The NVG group was adjunctively injected with intravitreal ranibizumab/bevacizumab (IVR/IVB) before AGVI. Intraocular pressure (IOP) was the primary outcome measure in this study. Surgical success rate, number of antiglaucoma medications used, best corrected visual acuity (BCVA), and postoperative complications were analyzed between the groups.ResultsAll of the patients completed the study (follow-up of 12 months). Kaplan-Meier survival curve analysis indicated that the qualified success rates in the NVG and non-NVG groups at 12 months were 70.5% and 92.9%, respectively; this difference was significant (P=0.036). The complete success rates in the NVG and non-NVG groups at 12 months were 66.7% and 89.3%, respectively (P=0.049). Compared with preoperative examinations, the postoperative mean IOP and use of medications were significantly lower at all follow-up time points in both groups (allP<0.05). There were significant differences in BCVA between the two groups at the 12-month follow-up (χ2=9.86,P=0.020). Cox proportional hazards regression showed NVG as a risk factor for surgical failure (RR=15.08,P=0.033). Postoperative complications were similar between the two groups.ConclusionsAGVI is a safe and effective procedure in refractory glaucoma, but the success rate of surgery was related to the type of refractory glaucoma. The complete and qualified success rates of NVG patient adjunctive anti-vascular endothelial growth factor treatment are still lower than those of non-NVG patients.