ABSTRACT
AIMS: The aim of this study was to evaluate the correlation between water-drinking test (WDT) outcomes and body mass index (BMI) in primary open-angle glaucoma (POAG) patients. METHODS: This study enrolled 41 POAG patients (41 eyes) under glaucoma treatment. POAG was defined as any typical signs of glaucomatous optic neuropathy and/or visual-field finding, with open angle on gonioscopy. After inclusion, patients underwent weight and height measurements. The WDT was performed, consisting of a baseline intraocular pressure (IOP) measurement, followed by the ingestion of 1 L of tap water within 5 min. Then, IOP was measured four times, at 15-min intervals. IOP peak was considered the maximum value of the four measurements, and IOP fluctuation was defined as the difference between the peak and the baseline IOP. RESULTS: The analysis of the IOP profile during the WDT revealed significant differences between groups with different BMIs. Patients with a higher BMI presented lower IOP peaks and fluctuation (P < 0.043; P < 0.001). There was also a significant correlation between the IOP fluctuation (both absolute [P < 0.024] and percentage [P < 0.021] values) and the following baseline parameters: BMI, weight, height, and cup-to-disc ratio. CONCLUSIONS: These data suggest that patients' individual characteristics, including BMI and weight, may influence the results of the WDT. In addition, patients with a higher BMI presented lower IOP fluctuation in the WDT.