The effect of lateral decubitus position on intraocular pressure in healthy young subjects

Abstract

Purpose: To investigate the effect of change of body posture from supine to lateral decubitus position (LDP) on intraocular pressure (IOP) in healthy young subjects. Methods: We evaluated 38 eyes of 19 healthy young Korean subjects. IOP was measured using Tonopen XL(R) in both eyes in the sitting and supine position, 5 and 30 min after right LDP and 5 min after returning to the supine position. A week later, IOP was measured in the same sequence except that the subjects assumed the left LDP. The eye on the lower side in the LDP was termed as a dependent eye. Results: The mean IOP of the dependent eyes increased significantly at 5 min after changing from supine to right (16.26 +/- 2.73 mmHg versus 18.54 +/- 2.95 mmHg, p < 0.01) or left LDP (15.53 +/- 2.41 mmHg versus 17.53 +/- 3.37 mmHg, p < 0.01); this IOP increase in the dependent eyes persisted at 30 min after changing to right (18.47 +/- 2.97 mmHg, p < 0.01) or left LDP (17.79 +/- 2.20 mmHg, p < 0.01). Upon returning to the supine position, IOP of the dependent eyes decreased significantly (16.83 +/- 2.67 mmHg, p < 0.01 for right LDP and 16.47 +/- 2.32 mmHg, p < 0.01 for left). However, this effect of the positional change was not found in the non-dependent eyes (all, p > 0.05). Mean IOP in the dependent eye was significantly higher than that in the non-dependent eye at 30 min after changing to the right (+ 0.89 +/- 1.52 mmHg) or left LDP (+ 1.84 +/- 2.03 mmHg). Conclusion: The postural change from supine to LDP significantly increased IOP of the dependent eyes.