Obstructive sleep apnea syndrome appears to alter the Hifα/Pparα/NF-κB signaling axis, affecting lacrimal gland structure and function and inducing dry eye, a study published in Investigative Ophthalmology & Visual Science suggests.
Researchers conducted studies in a murine model to determine the effect of obstructive sleep apnea syndrome on lacrimal gland function and the mechanism underlying related dry eye disease.
Cyclic intermittent hypoxia was used to mimic obstructive sleep apnea syndrome in male mice. A control group was housed in a separate, normal environment. The researchers used slit-lamp observation, fluorescein staining, and corneal sensitivity detection to assess corneal changes. They also evaluated tear secretion with phenol red cotton thread and pathological changes in lacrimal glands using hematoxylin and eosin staining, oil red O staining, cholesterol and triglyceride kits, immunofluorescence staining, immunohistochemical staining, real-time polymerase chain reaction, transmission electron microscopy, and Western blot.
The team found that the intermittent-hypoxia environment appeared to decrease tear secretion and induce corneal epithelial defects and hypersensitivity. They also observed changes in lacrimal glands, including epithelial cell damage, abnormal lipid accumulation, reduced cell proliferation, increased apoptosis, and inflammatory cell infiltration.
The researchers found that Hifα and NF-κB were upregulated and Pparα was downregulated in lacrimal gland tissue of mice from the intermittent-hypoxia environment compared with those from the control environment. The pathological changes of the lacrimal glands induced by the intermittent-hypoxia environment were significantly improved with fenofibrate treatment.
“Our study, for the first time, confirmed [a] causative relationship between [obstructive sleep apnea syndrome] and lacrimal gland dysfunction, and pointed out a potential clinical treatment for [obstructive sleep apnea syndrome]-related dry eye,” researchers report.
Wang S, He X, Li Q, et al. Obstructive sleep apnea affects lacrimal gland function. Invest Ophthalmol Vis Sci. 2022;63(3):3. doi:10.1167/iovs.63.3.3