Evaluation of the Effect of Body Position on Intraocular Pressure Measured with Rebound Tonometer

Abstract

Objectives:It is important to determine variables that influence intraocular pressure (IOP) measurement. This study aimed to evaluate the effect of body position on IOP.Materials and Methods:The study included 52 right eyes of 52 patients who presented to the ophthalmology department of our hospital and had no ocular disease except refractive errors. IOP was measured with an Icare PRO tonometer while patients were in sitting, standing, and supine positions, with intervals of 10 minutes between the positions. Correlations between the results were evaluated using Spearman’s correlation analysis and Wilcoxon tests.Results:Thirty-six of the 52 patients were female, 16 were male. Mean age was 31.65±6.30 (23-47) years. Mean IOP values in the sitting, standing, and lying positions were 17.76±3.41 (12.70-25.60) mmHg, 17.10±3.27 (11.50-25.20) mmHg, and 18.46±4.67 (10.50-29.40) mmHg, respectively. There were no statistically significant differences between measurements taken in the different positions (p=0.112, p=0.472, p=0.071). We observed that there was no relationship between age and body position (p>0.45, p>0.79, p>0.77) or between gender and position (p>0.59, p>0.69, p>0.54).Conclusion:Gender and age had no effect on IOP measured in different body positions. There were also no significant differences between IOP values measured in the different positions. Therefore, we believe the portable Icare PRO tonometer can be used for patients who are confined to bed and will provide IOP measurements that are concordant with values obtained while sitting.

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

“…It is possible that the influence of body position on the IOP result is lower in elderly people than in young people. This result confirms the findings of Mayali et al, 34 who reported that gender and age do not affect IOP measurements in different body positions (a group of subjects in the age range from 23 to 47 years old). However, there are studies in the literature in which the conclusions are in contrast with ours.…”

“…[17][18][19][20][21][29][30][31][32][33] This phenomenon began to be intensively considered and investigated some time ago due to the large number of bedridden patients requiring IOP measurements. However, the statistical significance of the difference between IOP measured in miscellaneous body positions is controversial, for example, Mayali et al 34 reported that the differences in IOP are not statistically significant in a group of healthy subjects. Other articles have shown that intraocular pressure measured in the supine position is significantly higher than the IOP values in the sitting or standing positions.…”

Difference in Intraocular Pressure between Sitting Versus Supine Positions in Healthy and Glaucomatous Children by Rebound tonometery

“…In this study, we found no significant correlation between IOP measurement and age of glaucomatous children, as well as, no significant relation between IOP measurement and gender of glaucomatous children. This goes in line with, Mayal et al 4 who demonstrated that, Gender and age had no bearing on IOP in various body postures.…”

Twenty Four Hour Intraocular Pressure Indicators Distinguish Normal Tension Glaucoma from Healthy Eyes Measured with a Contact Lens Sensor

“…The eyes' IOP is known to be fluctuate depending on the body position. 12 The IOP measurement with a contact lens sensor (CLS) has solved this problem. The Triggerfish CLS (Sensimed, Lausanne, Switzerland) was developed to continuously monitor habitual IOP fluctuations for a 24-hour period by measuring changes in the eye's circumference in the area of the corneoscleral junction.…”

“…Most of the investigations of IOP fluctuations have measured the IOP with Goldmann applanation tonometry (GAT) several times a day with the subject in a sitting position; however, such a method is inaccurate and lacks objectivity because it does not take into account the changes in a person’s body position and might not be able to measure the peak IOP. The eyes’ IOP is known to be fluctuate depending on the body position 12…”