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Prefer to snooze with a pair of pillows? New research suggests people with glaucoma could be quietly putting themselves at risk as they elevate their heads.
A study published in the British Journal of Ophthalmology this year found that sleeping with the head raised on two pillows was associated withhigher pressure inside the eye compared with sleeping flat on your back.
That pressure, otherwise known as intraocular pressure (IOP), is the primary risk factor for glaucoma progression.
Glaucoma is a group of eye diseases that damage the optic nerve, often due to fluid pressure build-up inside the eye, according to Glaucoma New Zealand. It is a leading cause of irreversible blindness, typically progressing without symptoms until significant vision loss has already occurred.
Glaucoma New Zealand estimates that over 100,000 New Zealanders have the condition, but only about half know they have it.
“The data are surprising,” Dr Thomas Johnson from Wilmer Eye Institute at Johns Hopkins University told MedPage Today, who was not involved in the research.
In the past patients have been recommended to sleep with pillows to increase the height of their head over their heart believing this would reduce their IOP overnight, said Johnson.
“The findings in this paper not only question the validity of that recommendation, but provide a plausible mechanism for why sleeping with the head elevated might actually increase IOP as compared to sleeping totally flat,” he told MedPage Today.
Researchers measured eye pressure in 144 glaucoma patients in two positions: lying flat, and with the head elevated on two pillows. Two-thirds of patients recorded higher eye pressure in the raised position.
The researchers believe the jugular vein becomes compressed when the head flexes forward, causing fluid to build up inside the eye.
The researchers described their findings as preliminary and called for further study. They suggested glaucoma patients may benefit from avoiding sleep positions that compress the jugular veins but stopped short of specific advice on pillow numbers.
Johnson said people with glaucoma should sleep in whatever way they are most comfortable, as there was not strong enough evidence to recommend one way or another.
Glaucoma New Zealand general manager Pippa Martin agreed with Johnson’s advice. She said one of the most important things to do was to get checked as sight loss from glaucoma is irreversible and incurable.
“Anyone 40+ should have regular eye health checks (not just an eye test) so that glaucoma can be found early enough to minimise vision loss,” said Martin.
Although sleeping with two pillows may not be good for people with glaucoma, it is often recommended for other conditions. For example, an elevated head can help decrease acid reflux and offer relief from snoring, according to the Sleep Foundation.
