Correlation of Asymmetric Glaucomatous Visual Field Damage and Water-Drinking Test Response

Abstract

To determine whether there is a correlation between asymmetric glaucomatous visual field (VF) damage and water-drinking test (WDT) response. A retrospective analysis was conducted of VF and WDT data from 101 patients with glaucoma in clinical therapy, who were receiving treatment with the same topical medication in both eyes, and asymmetric VF defect. Eyes were classified according to mean deviation (MD) into "better" and contralateral "worse" eyes. Maximum mean difference in basal IOP was 2 mm Hg between both eyes. The peak IOP and fluctuation obtained with the WDT were compared between both groups. For the statistical analysis, the Tukey post hoc multiple comparison test and paired t-test were used. Better and contralateral worse eyes presented mean MDs of -4.6 +/- 5.3 and -9.0 +/- 7.4 dB, respectively (P < 0.001). Mean basal IOPs were 13.9 +/- 3.3 and 13.9 +/- 3.1 mm Hg, respectively (P = 0.67). Mean maximum IOPs after water ingestion were 16.5 +/- 3.8 mm Hg in the group with less severe VF defect and 17.2 +/- 4.1 mm Hg in the contralateral group with worse visual fields (P < 0.001). Mean fluctuation (maximum IOP - minimum IOP after water ingestion) was 3.6 +/- 1.8 and 4.4 +/- 2.2 mm Hg (P < 0.001), respectively. Eyes with worse MDs presented higher IOP peaks and fluctuation after water ingestion. This study demonstrates a lower capacity of eyes with worse glaucomatous lesion to respond to a stimulus that leads to a transitory elevation of IOP.