A meta-analysis by researchers in China found individuals with dry eye disease (DED) had worse sleep quality and a higher risk of unhealthy sleep duration compared with healthy individuals.

Published in BMC Ophthalmology, the study by researchers from the Beijing Institute of Ophthalmology evaluated 21 studies with 419,218 participants. Despite finding no differences between healthy individuals’ and DED patients’ sleep duration, sleep efficiency, daytime dysfunction and sleep medication scores, they found the risk of sleep disorders was significantly higher in DED subjects.

DED patients’ poor sleep qualities may be due to light exposure and discomfort caused by incomplete eyelid closure or pain due to inflammation, said the research team. Dry mouth discomfort experienced by DED and Sjögren syndrome patients is also a contributing factor, plus sleep disorders often reduce tear secretion, they said. “At the same time, dry eye patients are more likely to suffer from anxiety and depression, with a prevalence of about 29%… (which) can also cause sleep disturbance.” However, there is not yet enough evidence to establish a causal relationship, they said.