2% ibopamine vs. water-drinking test as a provocative test for glaucoma

Purpose: To compare the 2% ibopamine provocative test with the water drinking test as a provocative test for glaucoma. Methods: Primary open-angle glaucoma patients and normal individuals were selected from CEROF-Universidade Federal de Goiania UFG, and underwent the 2% ibopamine provocative test and the water drinking test in a randomized fashion, at least 1 week apart. Intraocular pressure (IOP) before and after both tests, Bland-Altman graph, sensitivity and specificity (as mesured by ROC curves) were obtained for both methods. Results: Forty-seven eyes from 25 patients were included (27 eyes from 15 glaucoma patients and 20 eyes from 10 normal individuals), with a mean age of 54.2 +/- 12.7 years. The mean MD of glaucoma patients was -2.8 +/- 2.11 dB. There was no statistically difference in the baseline IOP (p=0.8) comparing glaucoma patients, but positive after the provocative tests (p=0.03), and in the IOP variation (4.4 +/- 1.3 mmHg for ibopamine and 3.2 +/- 2.2 mmHg for water drinking test, p=0.01). There was no difference in all studied parameters for normal individuals. The Bland-Altman graph showed high dispersion comparing both methods. The areas under the ROC curve were 0.987 for the ibopamine provocative test, and 0.807 for the water-drinking test. Conclusion: In this selected subgroup of glaucoma patients with early visual field defect, the ibopamine provocative test has shown better sensitivity/specificity than the water drinking test.