Impact of Sleep Position on Intraocular Pressure in Glaucoma Patients: A Novel Insight

A recent study found that sleeping without pillows was associated with a mean 1.61 mm Hg lower nocturnal intraocular pressure (IOP) in glaucoma patients. The observational finding may relate to nocturnal IOP spikes that contribute to progressive optic nerve damage, but it does not establish causation.

In a controlled overnight assessment, patients underwent repeated two-hourly IOP measurements while supine with and without pillows. The report linked pillow use to higher nocturnal IOP readings and greater fluctuation: elevated-position IOP averaged 17.42 mm Hg versus 16.62 mm Hg (mean increase ≈ 1.61 mm Hg), and ocular perfusion pressure was lower in the elevated condition. The cohort included adults across age bands and common glaucoma phenotypes.

This magnitude of difference may be clinically relevant, but guideline-based thresholds and confirmatory studies are needed before it should alter treatment decisions.

Why would a pillow matter? Neck flexion from stacked pillows can compress the jugular veins, impair ocular venous outflow, and reduce aqueous humor drainage—providing a plausible physiologic route to higher nocturnal IOP. Hemodynamic assessment in a subset demonstrated reduced jugular lumen and altered flow with head elevation, supporting the mechanistic chain from posture to venous congestion to pressure rise.

The study is limited by its observational design, modest subgroup sizes, and potential selection and measurement biases that restrict causal inference and generalizability. Variability in measurement timing, pillow height, and the predominance of certain glaucoma subtypes could affect effect estimates; residual confounding from medication timing or sleep-disordered breathing cannot be excluded. Larger randomized or crossover trials with standardized pillow elevation, stratified glaucoma subtypes, and extended monitoring are needed to define magnitude, durability, and patient selection before routine behavioral recommendations are adopted.

Key Takeaways:

• Sleeping with elevated head position from pillows increased nocturnal IOP by roughly 1.6 mm Hg and reduced ocular perfusion pressure in this observational cohort.
• Neck flexion and jugular venous compression provide a plausible physiologic mechanism linking pillow use to nocturnal IOP elevation.
• Larger randomized or crossover studies with standardized monitoring are required before changing routine clinical practice.