Level of vascular endothelial growth factor in aqueous humor and surgical results of Ahmed glaucoma valve implantation in patients with Neovascular glaucoma

Purpose: To determine the associations between the levels of growth factors in aqueous humor and the surgical outcomes of Ahmed glaucoma valve implantation in patients with neovascular glaucoma (NVG). Methods: From 19 NVG eyes of 19 patients, a sample of aqueous humor was taken just before Ahmed glaucoma valve implantation. Levels of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β1, and TGF-β2 in aqueous humor aspirates were measured using a sandwich enzyme-linked immunosorbent assay method. When the postoperative intraocular pressures were ≥21mm Hg with or without antiglaucoma medications at 2 successive visits or when any other surgical interventions were needed to lower intraocular pressure, that surgery was considered a failure. After patients were classified into success versus failure groups, the levels of the growth factors between the 2 groups was compared. The cumulative probability of success according to Kaplan-Meier analysis was also determined. Results: Mean postoperative follow-up period was 40.9±19.6 months and cumulative probability of success was 43% at 57 months after surgery. Mean VEGF level in the failure group was higher than that of the success group (P=0.014). However, there was no statistical difference in the levels of TGF-β1, TGF-β2, and protein between 2 study groups (all P>0.05). Conclusions: The level of VEGF in aqueous humor was significantly higher in the failure group after the Ahmed glaucoma implantation compared with the success group. Our results imply that VEGF may play a role in determining surgical success after Ahmed valve implantation in patients with NVG.