Does body position, age, and heart rate induce IOP's changes?

Abstract

The main goal of this research was to determine the differences between the values of intraocular pressure (IOP) in the supine and sitting positions, and to assess the effect of age and cardiovascular parameters. Seventy-two healthy adults were enrolled and classified into age groups: 20-30 years (group A), 31-40 years (group B), and 41-71 years (group C). Corneal biometry and cardiovascular parameters, such as heart rate (HR), were measured. IOP measurements were taken in the sitting position (IOPS) and in the supine position (IOPL) using the iCare® Pro tonometer. A significant difference between the IOPS and IOPL in the entire cohort was found (p < 0.001). Regarding the age subgroups, a significant difference (p < 0.001) between the IOPS and IOPL was obtained in group A (2.6 ± 1.6 mmHg) and group C (1.5 ± 1.3 mmHg). There were no significant differences in the IOPS between groups. The highest IOP values were obtained for group A. The correlations between HR and IOPS are statistically significant for group A and group B, and for HR and IOPL-S for group B only. Multivariate analysis showed that HR has a significant influence on the difference in IOP in the two body positions. A statistically significant difference between the effect of age and the values of IOPS and IOPL was shown. Cardiovascular parameters showed some relevant statistical dependencies, but with a rather marginal significance in young people. The influence of body position for the measurement of IOP for healthy subjects does not seem to matter, despite the fact that there are some dependencies that are statistically significant.