Evaluation of the diurnal intraocular pressure fluctuations and blood pressure under dehydration due to fasting

This study aimed to investigate the diurnal intraocular pressure fluctuations under dehydration conditions and the relationship between the intraocular pressure fluctuations and blood pressure.
The intraocular pressures (IOP), body weights, as well as systolic and diastolic blood pressures (SBP, DBP) of 36 fasting healthy volunteers were recorded at 8:00 a.m. and 5:00 p.m. in the Ramadan of 2014 and two weeks after it. The data were analyzed using paired Student’s t-test and Pearson correlation analysis.
As the results demonstrated, the mean diurnal IOP differences of IOP, SBP, DBP, and weight were 2.67±1.33 mmHg, 9.44±8.02 mmHg, 3.33±5.94 mmHg, and 0.90±0.46 kg during the fasting period, respectively. In addition, the mean diurnal IOP differences of IOP, SBP, DBP, and weight were -0.33±1.4 mmHg (P=0.001), 0.55±7.25mmHg (P=0.003), -3.33±5.94 mmHg (P=0.001), and 0.12±0.45 kg (P=0.001) during the control period, respectively. There was a moderate correlation between the diurnal IOP and SBP differences (r=0.517, P=0.028).
Based on the findings of the current study, the total fluid volume might have a more dominant effect on IOP peaks than the sympathetic system activity. Furthermore, the SBP was found to correlate with the IOP.