There has been a lot of discussion and research lately about glaucoma and sleep disorders. Factors such as sleep apnea, sleep duration and the length of time it takes a person to fall asleep have all been linked as a risk factor for developing glaucoma or a consequence of having glaucoma. This blog will delve into the relationship between sleep and glaucoma. First, we will give a brief description of what glaucoma. We will then discuss why we sleep, followed by discussion of circadian rhythm. Finally, we will discuss how all of this is intertwined.
First what is glaucoma?
Glaucoma is a disease of the optic nerve. This is the nerve in the back of the eye that is responsible for carrying all the visual information from the eye to the back of the brain, where it is processed into the pictures that we see. Glaucoma typically begins without any symptoms, making yearly eye exams important for anyone over the age of 50 or with a history of glaucoma in their family. Glaucoma often affects portions of our peripheral or side vision early on. When it affects larger or more central areas of our vision, we become symptomatic. Unfortunately, once symptoms occur they are likely permanent. If it is determined that you have glaucoma, there are numerous treatment options both medically and surgically that can help treat the disease. Learn more about glaucoma here: https://www.summiteyekc.com/blog/what-is-glaucoma
Importance of sleep
During sleep our body sort of reboots. It is during sleep that our immune, nervous, skeletal and muscular systems rebuild themselves so that we are ready for the next day. This process has been shown to be vital to maintain stability of our mood, memory and cognitive function. Our internal circadian clock promotes our body’s sleep each evening. Learn more about sleep here: https://www.sleepassociation.org/about-sleep/how-important-is-sleep/
Our circadian clock is located in an area of the brain called the hypothalamus. The retina within the eye contains photoreceptors that are responsible for vision. The retina also contains special photosensitive cells that communicate directly with the hypothalamus, where they help in “setting” our circadian clock. The retina essentially provides the hypothalamus with the lengths of daytime and nighttime. The hypothalamus sends this information to the pineal gland, which produces the hormone melatonin. The secretion of melatonin is greatest at night and lessens during the day.
It appears that glaucoma can lead to damage of the photosensitive cells within the retina. This results in a decrease in sleep quality among patients with glaucoma. People with cognitive problems during the day due to sleepiness are more likely to have a visual field defect related to glaucoma.
Sleep apnea has also been associated with glaucoma. Glaucoma patients with moderate to severe obstructive sleep apnea have been shown to have a higher level of progression of their glaucoma when looking at visual field loss as well as retinal nerve fiber loss on OCT testing.
This emphasizes the importance of doing what a person can to ensure a good night sleep. This can involve developing a nighttime routine to facilitate falling asleep, adjusting the temperature of your sleeping environment and eliminating blue light later in the evening.