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 µm, 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 (r² = 0,021) or between the central corneal thickness and the intraocular pressure fluctuation (r² = 0,011). Group 1 presented a mean central corneal thickness of 505,81 ± 13,86 µm, and Group 3 was 583,55 ± 27,87 µm (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.