Poor sleep linked to higher risk of vision loss

Credit: Hichem Dahmani/ Unsplash

Glaucoma is a leading cause of blindness and will likely affect an estimated 112 million people worldwide by 2040.

Characterized by progressive loss of light-sensitive cells in the eye and optic nerve damage, its causes and contributory factors are still poorly understood. But if left untreated, glaucoma can progress to irreversible blindness.

In a study from Beijing Huimin Hospital, scientists found poor quality sleep, including too much or too little shuteye, daytime sleepiness, and snoring, may be linked to a heightened risk of developing glaucoma.

Previously published research suggested that sleep disorders may be an important risk factor.

In the study, the team set out to ascertain the risk of glaucoma among people with different sleep behaviors: insomnia; too much or too little sleep; night or morning chronotypes (“owls” or “larks”); daytime sleepiness; and snoring.

They examined 409,053 participants in the UK Biobank, all of whom were aged between 40 and 69 in 2006-10 when recruited, and who had provided details of their sleep behaviors.

Sleep duration of 7 to less than 9 hours per day was defined as normal, and as too little or too much outside this range.

Chronotype was defined according to whether the person described themselves as more of a morning lark or night owl.

During an average monitoring period of just over 10.5 years, 8690 cases of glaucoma were found.

The team found those with glaucoma tended to be older and were more likely to be male, chronic smokers, and to have high blood pressure or diabetes than those who weren’t diagnosed with the disease.

With the exception of chronotype, the other sleep patterns/behaviors were all associated with varying degrees of heightened glaucoma risk.

Short or long sleep duration was associated with a heightened risk of 8%; insomnia, 12%; snoring, 4%; and frequent daytime sleepiness, 20%.

Compared to those with a healthy sleep pattern, snorers and those who experienced daytime sleepiness were 10% more likely to have glaucoma, while insomniacs and those with a short/long sleep duration pattern were 13% more likely to have it.

The team says there are potentially plausible biological explanations for the associations found between sleep disturbance and glaucoma.

The internal pressure of the eye, a key factor in the development of glaucoma, rises when a person is lying down and when sleep hormones are out of kilter, as occurs in insomnia.

Depression and anxiety, which often go hand in hand with insomnia, may also increase internal eye pressure, possibly because of dysregulated cortisol production.

Similarly, repetitive or prolonged episodes of low levels of cellular oxygen, caused by sleep apnea (sudden stopping of breathing during sleep), might cause direct damage to the optic nerve, it has been suggested.

If you care about sleep, please read studies about a new way to detect sleep apnea, and this sleep supplement may help prevent memory loss.

For more information about wellness, please see recent studies about drug that can treat sleep loss and insomnia, and results showing how vitamin B may help fight vision loss.

The study was conducted by Cun Sun et al and published in BMJ Open.

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