The Relationship between Sleep and Glaucoma
Sleep is a necessary part of our everyday lives, and while it is associated with being a period of rest and healing, many factors in sleep can contribute to negative effects on eyes. These factors include sleeping habits, positions, problems such as sleep apnea, and even the kind of pillow someone uses. More specifically, the progression of glaucoma — a group of eye conditions that elevate inner eye pressure to dangerous levels which damage the optic nerve and lead to vision loss, is one of the prominent issues affected by some of these factors.
A study published in 2019 by researchers from John Hopkins University investigated a hypothesis linking sleep problems and glaucoma using data compiled from the 2005-2008 National Health and Nutrition Examination Survey of the United States. More than 6700 glaucoma patients over the age of 40 were interviewed about their sleep habits, such as how long they slept or whether they had daytime dysfunction due to sleepiness. These patients were examined using fundus photography (multiple photographs of the inner eye taken through the pupil) to see the optic nerve and automated visual field testing to check for vision loss.
The hypothesis came after researchers confirmed a connection between chronic higher eye pressure and damage to ganglion cells in the retina. These cells were hypothesized to impact sleep and circadian rhythm. One of the reasons is because eye pressure is affected by the production and drainage of fluid in the eyes. This means eye pressure increases 10-20% during sleep because the drainage system is blocked when lying flat, even though eye fluid production decreases during sleep.
So what were the results? It turns out that glaucoma was three times more prevalent in those who slept for 10 hour or more, versus those who slept for 7 hours and less. This is because as mentioned in the previous paragraph, eye pressure increases during sleep. The study also found that people diagnosed with glaucoma were more likely to fall asleep very quickly or at a slower rate than others. Those with glaucoma either fell asleep in 9 minutes or less, or in 30 minutes or more, whereas the regular is 10-29 minutes. Lastly, the study suggested a connection between daytime sleepiness, where participants had difficulty performing daily tasks, with glaucoma.
Despite this research, it is important to note that having poor sleep habits does not necessarily indicate glaucoma. Contact a doctor if you are experiencing sleep issues and be sure to have regular eye check ups. Glaucoma is an eye disease that is hard to diagnose early on before vision loss, but it affects millions of people around the globe and is a serious cause of blindness and should therefore be taken seriously. Furthermore, while this study does indicate that poor sleep quality affects our eyes, additional research still needs to be done to verify this connection.