ABSTRACT
PURPOSE: To evaluate whether patients who have undergone trabeculectomy with mitomycin C have a different intraocular pressure (IOP) response profile after the water drinking test (WDT) from that of patients who are medically managed with a similar baseline IOP and level of visual field (VF) damage. DESIGN: Prospective observational study. PARTICIPANTS: Thirty glaucoma patients with IOP controlled by trabeculectomy and 30 with medically treated glaucoma matched for level of VF damage and IOP at baseline (7-14 mmHg). METHODS: All patients underwent the WDT, which involved drinking 1000 ml of water in 15 minutes. MAIN OUTCOME MEASURES: The IOP was measured before the WDT and subsequently at 15-minute intervals for 1 hour. The peak IOP with the WDT was compared between both groups using Tukey post hoc multiple comparison and paired t tests. RESULTS: Baseline IOPs were 10.4+/-2.3 mmHg in surgically treated and 11.1+/-1.8 mmHg (P = 0.07) in medically treated eyes. After the WDT, mean IOPs in the surgically and medically treated groups were 10.7+/-2.3 mmHg and 14.6+/-2.2 mmHg. Mean maximum IOPs were 11.7+/-2.6 mmHg and 17.3+/-2.7 mmHg in the surgically and medically treated groups, respectively (P<0.0001), increases of 12.5% and 56%. Ranges of IOP during the WDT were 2.2+/-1.3 mmHg and 5.6+/-1.9 mmHg in the surgically and medically treated patients (P<0.0001). CONCLUSIONS: Patients with advanced glaucoma who are medically controlled show greater IOP elevation and peak IOP after the WDT than eyes that have undergone trabeculectomy.
