Poor sleep increases the risk of glaucoma

By Nidhi Saha, BDSReviewed by Benedette Cuffari, M.Sc.Nov 8 2022

A recent BMJ Open study reports that snoring, daytime sleepiness, insomnia, and sleep duration may increase the risk of glaucoma.

Study: Association of sleep behavior and pattern with the risk of glaucoma: a prospective cohort study in the UK Biobank. Image Credit: SERGEI PRIMAKOV / Shutterstock.com

What is glaucoma?

Throughout the world glaucoma remains a primary cause of irreversible vision loss. With over 70 million people currently affected by glaucoma worldwide, researchers estimate that by 2040, this number will rise to over 111 million.

Glaucoma arises due to the progressive loss of retinal ganglion cells (RGCs), particularly intrinsically photosensitive RGCs (ipRGCs). Elevated intraocular pressure (IOP) is a significant risk factor for glaucoma; therefore, most therapeutic interventions aim to reduce IOP.

When in the supine position, such as during sleep, IOP is often at its peak. Previous reports indicate that IOP levels may increase by as much as 4 mmHg when glaucoma patients transition from sitting to lying.

These observations have been corroborated by several reports assessing sleeping patterns in glaucoma patients. For example, one study found that the prevalence of glaucoma was lowest among people who slept seven hours each night and highest among those who slept for less than three or more than 10 hours each night.

In addition to the impact of sleep on glaucoma, research has also shown that this disease can also impact the quality and quantity of sleep in patients, particularly among those experiencing severe forms of the disease.  To this end, a high prevalence of sleep disorders has been reported in glaucoma patients, the most common of which is obstructive sleep apnea (OSA).

About the study

To better understand the impact of different sleep behaviors on the risk of glaucoma, the researchers recruited over 500,000 individuals enrolled in the United Kingdom Biobank to complete questionnaires. In addition, baseline information on the participants’ sociodemographic, lifestyle, and health-related characteristics was collected at baseline.

Individuals who disengaged from the UK Biobank were previously diagnosed with glaucoma before the start of the study, previously underwent glaucoma surgery or laser treatment, or did not provide information on their sleep patterns were excluded from the study. From their initial recruitment date, all study participants were followed until a diagnosis of glaucoma, death, emigration, or March 31, 2021, whichever occurred first.  

Study findings

After the exclusion criteria were applied, 409,053 individuals were included in the final analysis. The mean age at recruitment was 57 years, with 45% of the total study cohort male.

The mean follow-up duration for the study participants was 10.7 years, at which point 8,690 glaucoma cases were identified. Glaucoma patients were more likely to be older, male, previous smokers, and have a history of hypertension or diabetes at the start of the study.

For the purposes of the current study, short sleep duration was defined as less than seven hours per day, whereas long sleep duration exceeded nine hours each day. Both short and long sleep durations were associated with an increased risk of glaucoma.

Furthermore, those who reported “usually,” which was the highest severity level for insomnia symptoms in this study, were also more likely to have glaucoma.

Frequent daytime sleepiness was also associated with an excess risk of glaucoma. Interestingly, daytime sleepiness was associated with primary open-angle glaucoma (POAG) but not primary angle-closure glaucoma (PACG). The impact of other sleep behaviors was similar between the different types of glaucoma.

Conclusions

The current study reports that individuals with poor sleep habits, including snoring, daytime sleepiness, insomnia, and short- and long-sleep durations, were more likely to develop glaucoma. These findings emphasize the importance of sleep intervention in high-risk glaucoma individuals and the benefits of routine ophthalmologic screening in those with chronic sleep disorders for glaucoma prevention.