Correlation between central corneal thickness and intraocular pressure peak and fluctuation during the water drinking test in glaucoma patients

OBJECTIVE: To investigate the correlation between central corneal thickness and outflow facility assessed by intraocular pressure peak and fluctuation during the water drinking test. METHODS: Fifty-five newly diagnosed primary open-angle glaucoma patients submitted to central corneal thickness measurements and water drinking test were enrolled in this retrospective study.;. Patients were divided into three groups according to their central corneal thickness. Pearson's Correlation test was performed in the groups with lower and higher pachymetric values. RESULTS: The mean age was 65,65 +/- 28,28 years; 63,63% were female and 52,72% were caucasian. The mean central corneal thickness was 544,32 +/- 36,86 mu m, and the mean baseline intraocular pressure was 23,36 +/- 6,26 mmHg. During the water drinking test, the mean intraocular pressure peak and mean intraocular pressure fluctuation were 30,43 +/- 8,13 mmHg and 31,46 +/- 18,46%, respectively. No relevant correlation was detected between the central corneal thickness and the intraocular pressure peak (r(2) = 0,021) or between the central corneal thickness and the intraocular pressure fluctuation (r(2) = 0,011). Group 1 presented a mean central corneal thickness of 505,81 +/- 13,86 mu m, and Group 3 was 583,55 +/- 27,87 mu m (p = 0,001). The mean intraocular pressure peak was 31,05 +/- 9,05 mmHg and 27,83 +/- 4,92 mmHg in Group 1 and in Group 3, respectively (p = 0,193). The difference of intraocular pressure fluctuation was not statistically significant between Group 1 (mean 28,47 +/- 16,25%) and Group 3 (mean 33,27 +/- 21,27%) (p = 0,43). CONCLUSION: In our case series, no correlation was found between central corneal thickness and water drinking test results.