Effect of Prophylactic Aqueous Suppression on Ahmed Glaucoma Valve Surgery Success

PURPOSE: To evaluate the effect of prophylactic aqueous suppressants immediately post-Ahmed glaucoma valve (AGV) surgery on the rate of hypertensive phase and success. METHODS: Retrospective case–control study of 80 eyes with refractory glaucoma undergoing AGV surgery. Forty eyes in the intervention group (preoperative aqueous suppressants continued postoperatively) and 40 in the control group (all glaucoma drops stopped after surgery and reintroduced as required) were included in this study. Patients were followed for 1 year. Data collected included intraocular pressure (IOP), number of glaucoma medications, and number of eyes requiring further IOP lowering surgery. The frequency of hypertensive phase and 1-year success was compared between the groups. RESULTS: Hypertensive phase occurred in 22.5% of the intervention group compared to 42.5% of the control group; however, this difference was not statistically significant (P = 0.06). Success at 1 year (IOP ≤21 mmHg but ≥5 mmHg and 20% reduction from baseline without additional surgery) was similar in each group: 77.5% in the intervention group and 62.5% in the control group (P = 0.22). However, at 1 year, significantly more eyes in the intervention group had an IOP ≤17 mmHg (95% vs. 80%, P = 0.04). The mean time interval to a second IOP lowering procedure was significantly shorter in the control group (P < 0.005). CONCLUSIONS: With prophylactic preoperative aqueous suppressants, more eyes achieved an IOP of ≤17 mmHg. The time interval to repeat the glaucoma procedure was significantly shorter in the control group.