Glaucoma is a progressive optic neuropathy, and increased intraocular pressure (IOP) is an important modifiable risk factor. IOP differs throughout the day, typically increasing at night, and is significantly affected by body posture during sleep. Studies have shown that transitioning from an upright to supine position increases IOP, with even greater elevations observed in the lateral and prone positions. Semi-reclined positions by using wedge pillows can help to reduce IOP, but they are impractical. However, they are often impractical for long-term use. Consequently, there is growing interest in simple, patient-centered approaches that may complement conventional glaucoma treatments. The effect of sleeping with a high pillow position on nocturnal IOP remains uncertain.
The aim of this study was to assess the effect of high pillow sleeping position on nocturnal IOP, 24-hour IOP fluctuation, and ocular perfusion pressure (OPP) in patients with glaucoma and ocular hypertension. Additionally, the study sought to identify clinical factors associated with postural IOP changes and to explore potential mechanisms by assessing jugular venous hemodynamics.
This prospective observational study was conducted in accordance with the Declaration of Helsinki and involved consecutive patients undergoing 24-hour IOP monitoring from October 2023 to April 2024. Patients diagnosed with open-angle glaucoma (POAG), normal-tension glaucoma (NTG), or ocular hypertension (OHT) were enrolled based on standard structural, functional, and gonioscopic criteria. Exclusion criteria involved secondary glaucoma, angle closure disease, ocular trauma, corneal abnormalities, and poor cooperation during measurements. A total of 144 patients were analysed, with the right eye selected for consistency.
IOP was measured every 2 hours for a 24-hour period by using the Care IC200 rebound tonometer by a single trained examiner. Patients continued their prescribed topical IOP-lowering therapy. Daytime measurements were obtained in a sitting position. IOP was first measured in the supine position during nocturnal assessment and after 10 minutes in the high pillow position, defined as head elevation of about 20 to 35° by using 2 standard pillows while keeping the shoulders flat on the bed. Four paired nocturnal measurements were obtained for each position. Blood pressure was measured concurrently, and OPP was calculated by using position-specific formulas.
Ultrasonography of internal and external jugular veins was performed in 2 healthy volunteers in both supine and high pillow positions to assess venous diameters, cross-sectional areas, and maximum blood flow velocities. Statistical analysis was performed by using SPSS. Data distribution was assessed with the Kolmogorov-Smirnov test. Positional comparisons were conducted by using paired t-tests or Mann-Whitney U tests. Postural IOP change was defined as the absolute difference between high pillow and supine IOP. Subgroup comparisons were performed by using Mann-Whitney U and Kruskal-Wallis tests with Bonferroni correction. Univariate and multivariate linear regression analyses were used to detect factors linked with the natural logarithm of ΔIOP, with statistical significance set at p < 0.05.
Of the 155 patients initially enrolled, 144 were included in the final analysis. Overall, 66.7% of patients showed an elevation in IOP when transitioning from supine to high pillow position with a mean increase of 1.61±1.31 mm Hg. Mean nocturnal IOP was higher in the high pillow position than in the supine position, and this posture was linked with higher 24-hour IOP function. OPP was significantly reduced in the high pillow position, which indicates potentially compromised ocular perfusion. The median postural IOP change (ΔIOP) was 1.88 mm Hg. Subgroup analyses showed that younger patients showed larger ΔIOP than older adults, and patients with POAG had significantly greater postural IOP changes than those with NTG. Univariate regression analysis detected younger age, thicker central corneal thickness (CCT), higher baseline and 24-hour IOP parameters, and greater 24-hour IOP fluctuation as factors associated with larger ΔIOP. Multivariate regression models demonstrated that thicker CCT and POAG diagnosis were independent predictors of greater postural IOP change.
Jugular vein ultrasonography showed that the high pillow position reduced the diameter and cross-sectional areas of both external and internal jugular veins with concomitant increase in internal jugular vein blood flow velocity consistent with mechanical venous compression.
In conclusion, sleeping in a high-pillow position is associated with elevated nocturnal IOP, increased 24-hour IOP fluctuation, and reduced ocular perfusion pressure in patients with glaucoma and ocular hypertension. These effects appear to be mediated by neck flexion-induced jugular venous compression, which may impair aqueous humour outflow. Avoiding sleep postures that promote neck flexion may represent a simple, practical, non-pharmacological adjunct to optimise long-term IOP management in glaucoma care.
Reference: Liu T, Hu M, Liu X, et al. Association of high-pillow sleeping posture with intraocular pressure in patients with glaucoma. Br J Ophthalmol. 2026. doi:10.1136/bjo-2025-328037
