Early Aqueous Suppressant Therapy on Hypertensive Phase Following Glaucoma Drainage Device Procedure: A Randomized Prospective Trial

Purpose: To prospectively evaluate the effect of early aqueous suppression (therapy) on hypertensive phase (HP) and intraocular pressure (IOP) control after implantation of silicone Ahmed glaucoma valve (AGV). Materials and Methods: Patients who underwent AGV implantation were randomized to initiate therapy (including beta-blockers, alpha-agonists, or carbonic anhydrase inhibitors) when postoperative IOP > 10 mm Hg (low-IOP initiation group) or > 17 mm Hg (moderate-IOP initiation group). HP was defined as an IOP > 21 mm Hg during the first 6 postoperative months, after an initial IOP reduction to <22 mm Hg in the first postoperative week. Primary outcome measures included the occurrence of HP and IOP control. Results: Fifty-two eyes (50 patients) underwent AGV implantation. Average follow-up was 21.9 +/- 10.7 months. HP was observed in 21 eyes (40.4%) with average peak IOP of 30 +/- 8 mm Hg, onset at 32 +/- 30 days, and duration of 15 +/- 32 days. One year postoperatively, those eyes with HP had higher IOP than eyes that did not develop HP (15.1 +/- 5.2, 11.4 +/- 4.3, respectively; P = 0.021) and required more additional glaucoma surgeries (28.6%, 3.2%, respectively; P = 0.013). The peak IOP at week 3 postoperatively in the low-IOP initiation group (26 eyes) was significantly lower than in the moderate-IOP initiation group (26 eyes; 15.7 +/- 3.6, 20.6 +/- 8.9, respectively; P = 0.012). Eyes with therapy started after HP onset had significantly higher postoperative IOP from 2 to 4 months. Therapy initiated before the development of HP was not associated with a higher complication rate. Conclusions: Aqueous suppression initiated in the early postoperative period while IOPs were still in the low-teens and was able to reduce the incidence of IOP spike associated with the HP without an increased complication rate.