Can Sleep Apnea Increase the Risk of Normal-Tension Glaucoma?

Sleep apnea and glaucoma may seem unrelated, but researchers are uncovering an important connection between nighttime breathing interruptions and eye health. Research has linked obstructive sleep apnea (OSA) to a higher risk of glaucoma, including normal-tension glaucoma, which damages the optic nerve even when eye pressure remains within the normal range. Understanding what happens in the eyes during sleep could help researchers explain this puzzling disease and identify better ways to protect vision.

OSA is also associated with serious conditions such as heart attack and ischemic stroke, leading researchers to ask what these seemingly different disorders may have in common. Detecting and treating sleep apnea can provide substantial cardiovascular and quality-of-life benefits. Appropriate treatment may also support glaucoma care for some patients, although researchers still need to clarify the relationship between sleep apnea treatment and glaucoma progression. 

By studying the physical changes that occur during apnea episodes, they hope to uncover insights that could eventually improve glaucoma treatment. Reaching that goal will require careful consideration of many factors, as well as innovative technology to help clarify the true connection.

Glaucoma is a group of eye diseases that damage the optic nerve, which carries visual information from the eye to the brain. The condition often develops without early symptoms and can gradually cause permanent vision loss. Although high eye pressure is a major risk factor, glaucoma can also develop when pressure remains within the normal range. Regular comprehensive eye exams can detect damage early, when treatment may help protect remaining vision.

Because elevated intraocular pressure, or IOP, is a major glaucoma risk factor, researchers often examine it first when glaucoma appears connected to another condition, such as OSA. Until recently, however, studying overnight changes in eye pressure was difficult. Repeated measurements could disrupt sleep, cause discomfort, and affect the accuracy of the results.

A newer contact lens sensor offers a less disruptive way to monitor changes throughout the day and night. The lens responds to subtle shifts in the cornea’s shape and circumference, which can reflect changes in IOP. These movements generate electrical signals indicating whether pressure is rising or falling.

By continuously tracking these patterns without repeatedly waking the patient, researchers can study how eye pressure changes during sleep and apnea episodes. They hope the technology will provide clearer insight into the connection between OSA and glaucoma.

By combining the contact lens sensor with polysomnography, which tracks breathing, oxygen levels, and other aspects of sleep, researchers can simultaneously measure apnea events and changes in intraocular pressure.

Researchers expected IOP to rise during apnea events, but the limited evidence has been mixed. One small study observed pressure declines in some patients, while a later study found no significant difference between apnea and non-apnea periods.

The findings suggest that the connection between OSAS and glaucoma may not stem from elevated eye pressure. Researchers are now exploring whether repeated drops in blood oxygen during apnea episodes may gradually damage the optic nerve.

Because this damage may occur without increased IOP, the research could also provide insight into normal-tension glaucoma. Oxygen deprivation may help explain why OSAS is associated not only with glaucoma, but also with heart attack and ischemic stroke.

People with sleep apnea symptoms or risk factors should consult a health care professional, as diagnosis may require a sleep study. Treatment can support cardiovascular health, improve alertness and quality of life, and potentially strengthen glaucoma care by addressing nighttime oxygen loss. However, researchers have not established whether treating sleep apnea prevents or slows glaucoma. Sleep apnea treatment should complement regular eye exams and prescribed glaucoma care.

The causes of normal-tension glaucoma remain unknown, but new theories are emerging. Much like primary open-angle glaucoma, without regular trips to the eye doctor to check the optic nerve for signs of damage, it may go unnoticed until significant vision loss has occurred. Earlier diagnosis and better understanding of this form of glaucoma may help preserve sight.

With novel discoveries and new technology to implement in studies of this disease, researchers may be able to uncover the underlying triggers of all varieties of glaucoma. The more that researchers understand about this challenging disease, the more likely they are to find a cure.

Researchers are still working to understand how sleep apnea may contribute to normal-tension glaucoma, but patients do not need to wait to take proactive steps. Comprehensive eye exams can identify glaucoma early, while sleep apnea evaluation and treatment can provide significant cardiovascular and quality-of-life benefits. For some patients, addressing both conditions may support more comprehensive glaucoma care.

Your support can help accelerate that progress. By donating cash, stock, or a vehicle, you can give hope to people living with glaucoma and help researchers advance new treatments, restore vision, and protect sight for future generations.

Revised and updated August 10, 2026. Reviewed for medical accuracy by Davinder S. Grover, MD, MPH.