Obstructive sleep apnea (OSA) is already linked to snoring, daytime fatigue, and heart risk — but researchers are increasingly asking whether it might also affect eye health, especially glaucoma.
That concern is not new.
In fact: A 2023 systematic review and meta-analysis found OSA was associated with higher glaucoma risk, adding to questions about whether sleep-related breathing problems may influence optic nerve health.
And with that in mind …
A recent real-world cohort study published in Ophthalmology Glaucoma adds more evidence to that discussion, finding that OSA had a higher incident glaucoma risk—regardless of whether they were using a positive airway pressure (PAP) device.
So why this connection?
OSA involves repeated upper airway collapse during sleep, which can lead to oxygen desaturation and disrupted sleep. Those repeated episodes have raised questions about whether intermittent hypoxia, vascular dysregulation, and other systemic effects could influence the optic nerve.
And while intraocular pressure (IOP) remains a major treatment target in glaucoma, vascular and non-IOP factors may also contribute to disease risk or progression.
Explain how PAP therapy fits into this.
While PAP therapy is a standard treatment for adults with OSA, previous studies have raised concerns that CPAP therapy, the most commonly prescribed form of PAP, may influence intraocular pressure (IOP) in certain patients.
Let’s circle back to this new research — what was studied?
Investigators evaluated the association between OSA, PAP device records, and incident glaucoma using Epic Cosmos, a large multicenter electronic health record (EHR) database.
Adults were grouped into three categories:
- Sleep-tested controls without OSA
- Patients with OSA but no PAP device record
- Patients with OSA and a PAP device record within 180 days
Follow-up began 180 days after the index OSA evaluation. Researchers then tracked patients until incident glaucoma, death, or last recorded encounter.
Incident glaucoma was defined as at least two glaucoma diagnosis codes within 365 days, with the first qualifying diagnosis occurring after the 180-day landmark.
So who were these participants?
The study included 12,516,607 adults with an index encounter for OSA evaluation between Jan. 1, 2010, and Oct. 31, 2025. The inclusion criteria:
- No prior glaucoma diagnosis
- At least 180 days of follow-up
- Sleep testing or clinical evaluation related to OSA
The cohort had a mean age of 60.4 years, and 43.7% of participants were women.
… and what did the researchers find?
Over an average follow-up of 5.2 years, researchers identified 153,083 incident glaucoma events.
Crude glaucoma incidence rates per 1,000 person-years were:
- 1.74 among sleep-tested controls
- 2.38 among OSA patients without a PAP device record
- 3.39 among OSA patients with a PAP device record
Compared with sleep-tested controls, adjusted glaucoma risk was higher in both OSA groups. Patients with OSA but no PAP device record had a hazard ratio (HR) of 1.27, while patients with OSA and a PAP device record had a HR of 2.10.
At 10 years, cumulative glaucoma incidence was:
- 1.58% in controls
- 2.30% in OSA patients without a PAP device record
- 3.86% in OSA patients with a PAP device record
Does that mean PAP therapy increases glaucoma risk?
Not necessarily. The authors were careful not to interpret the higher risk in the PAP-record group as proof that PAP therapy itself caused glaucoma.
PAP exposure was based on EHR codes—not direct device data—and patients prescribed PAP were often those with more severe or symptomatic OSA.
And that creates a problem?
An important problem called confounding by indication.
In other words: The higher glaucoma risk in the PAP-record group may reflect underlying OSA severity, treatment indication, comorbidity burden, or differences in follow-up patterns rather than a harmful effect of PAP itself.
This is especially important because PAP therapy remains a recommended treatment for many adults with OSA.
- To note: The study was more informative about the association between OSA and glaucoma risk rather than about whether PAP increases or decreases that risk.
Explain this possible OSA-glaucoma connection
The exact mechanism remains unclear, but several possible pathways have been proposed.
One theory: intermittent hypoxia. Repeated oxygen desaturation during sleep could contribute to vascular dysregulation, oxidative stress, and reduced optic nerve resilience.
- These mechanisms may be especially relevant if glaucoma risk is not driven by intraocular pressure alone.
And another concern?
Prior research has also linked OSA with normal-tension glaucoma (NTG), supporting the idea that non-IOP mechanisms may matter in at least some patients.
- For instance: A prospective study found a higher prevalence of OSA among patients with NTG than controls.
At the same time, PAP therapy has drawn attention because some studies have reported IOP changes in patients using continuous PAP (CPAP).
Case in point: One earlier study found that CPAP therapy was associated with increased IOP in patients with OSA, although the long-term clinical significance of those pressure changes remains uncertain.
Any other limitations to the study?
The biggest limitation: its observational design—meaning it could show association but not prove that OSA directly causes glaucoma or that PAP therapy changes glaucoma risk.
Another limitation: PAP use was defined through EHR coding rather than direct device monitoring
- Translation: It could identify a PAP device record but not confirm how often patients actually used the device.
Next up: the takeaways.
The authors concluded that OSA was associated with a higher risk of incident glaucoma compared with sleep-tested controls.
They also suggested that ophthalmic monitoring may be warranted in patients undergoing clinical evaluation or treatment for OSA—but that does not mean every patient with OSA will develop glaucoma, and the absolute risk still remains relatively low.
Nevertheless: Eyecare providers may want to pay closer attention to glaucoma risk in this population.