Stacked pillows could alter your neck position while you sleep, which can compress the jugular vein and increase internal eye pressure – which can lead to blindness
Sleeping without pillows may reduce eye pressure and prevent glaucoma, research suggests.
A trial showed that stacked pillows alter the neck position which can compress the jugular vein and prevent natural drainage of fluid in the eye. This increases internal eye pressure which can lead to optic nerve damage and glaucoma. Over a millions Brits are estimated to have glaucoma and the condition is a risk for people aged over 40 and can lead to blindness if untreated.
Scientists say sleeping with your neck on an angle on top of multiple stacked pillows can contribute to the condition and suggest glaucoma patients may benefit from sleeping with no pillows or a single, thin pillow. Blood flow brings oxygen and vital nutrients to the eye to keep it healthy but this fluid needs to be easily flushed through and out of the eye.
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The study, published in the British Journal of Ophthalmology, included 144 people with glaucoma and found eye pressure increased by two thirds when they lay with heads raised by 20-35 degrees by two pillows, when compared to lying flat with no pillows.
The position was also linked to an increased fluctuation in eye pressure over 24 hours and a fall in the pressure at which blood enters the eye. Ultrasound scans were also carried out on another 20 healthy volunteers who did not have glaucoma and showed the high pillow position caused “significant constriction” of the jugular vein, which takes blood from the head back to the heart.
Researchers said people with glaucoma “may benefit from avoiding sleeping postures” that cause this increase in internal eye pressure, formally known as intraocular pressure, or IOP for short.
Study author Dr Kaijun Wang, of Eye Center of Second Affiliated Hospital at the Hangzhou School of Medicine in Zhejiang, China, said: “Patients with glaucoma may therefore benefit from avoiding sleeping postures that induce jugular venous compression to mitigate postural IOP elevation. Such behavioural adjustments represent a simple yet potentially effective adjunctive strategy for optimising long-term IOP management in clinical practice.”
Internal eye pressure fluctuates in response to changes in body posture and the move from a generally upright posture to lying down is the main cause of its increase at night, researchers said.
To explore this further they looked at the effect on IOP of sleeping with two regular sized pillows, providing a head elevation of 20–35 degrees in 144 adults with glaucoma. Some 84 of the participants were aged under 44.
Their right eye IOP was measured every two hours for 24 hours, both when sitting and when lying down. When lying down, their heads were raised to an elevation of between 20 degrees and 35 degrees by two normal sized pillows and they had their IOP measured 10 minutes later.
Participants then reverted to sleeping on their backs until the next measurement. Four sets of complete measurements were obtained for each, with and without pillows.
The results showed 67% of participants showed an increase in IOP when moving from lying flat without pillows to an elevated pillow position. Eye pressure was significantly higher in the elevated position.
When the results were analysed they showed that young adults were much more likely to have significantly raised IOP as a result of the posture change than older adults.
Glaucoma typically develops slowly without early symptoms, initially affecting peripheral vision. Previous research estimated that glaucoma cases in Britain could rise by 60% to 1.6 million by 2060. It can be treated with daily eye drops, laser treatment or surgery to lower eye pressure.
Researchers from UCL and Moorfields Eye Hospital estimate that 1.1 million people in the UK currently have the condition, the equivalent of 3% of the population over the age of 40.
