The FINANCIAL -- A new study examines the link between Sjögren's syndrome, dry eye disease and depression.
"If this is the case, then there is a significant unmet clinical need that allows us to clinically differentiate between dry eye and neuropathic pain."
The study, "How Are Ocular Signs and Symptoms of Dry Eye Associated with Depression in Women with and Without Sjögren's Syndrome?" was published in the July 2018 issue of the American Journal of Ophthalmology. For their study, researchers from the University of California San Francisco and the University of Pennsylvania performed an analysis of participants in the Sjögren's International Collaborative Clinical Alliance (SICCA). That registry included about 3,500 participants, overwhelmingly women because the condition occurs more frequently in women. Nine out of 10 patients with Sjogren's are women, according to the Sjögren's Syndrome Foundation.
Among the researchers' findings:
Dry eye patients were associated with 1.82-fold higher odds of having depression versus "symptom-free" study participants.
Ocular sensations, such as gritty sensation, burning and/or light sensitivity, were also linked to higher odds (2.45-fold) of depression compared to those with no complaints.
"In conclusion, our finding that participant-reported eye symptoms were positively associated with depression while KCS (keratoconjunctivitis sicca) phenotypic features were not is consistent with previous reports," researchers said.
"Because depression and dry eye syndrome can both significantly decrease quality of life, it is important to better understand the relationship between these 2 diseases," they concluded, noting that additional research is needed so the findings may eventually improve treatment, as well as patients' quality of life.
Building on the science
Jillian Ziemanski, O.D., M.S., is clinical assistant professor in the School of Optometry at the University of Alabama at Birmingham. Among Dr. Ziemanski's teaching and research interests are Sjögren's syndrome and dry eye disease. Dry eye is the most common ocular manifestation of Sjögren's syndrome.
The link between dry eye disease and depression has been established, Dr. Ziemanski says. But this new study sheds light on the link between Sjögren's and depression, she adds.
"The significance of this paper is that it has great potential to serve as a foundation for future translational research," Dr. Ziemanski says. "It begs the question of which condition precedes the other. Do dry eye symptoms drive the onset of depression? Conversely, does depression stimulate immunologic hyperactivity and induce inflammatory dry eye disease?
"A second significant outcome of this study is that the authors present Sjögren's-associated ocular discomfort as being both dry eye disease and neuropathic ocular pain," Dr. Ziemanski adds. "If this is the case, then there is a significant unmet clinical need in diagnostic tools that allow us to differentiate between dry eye and neuropathic pain. Further, we currently have few to no treatment options for neuropathic ocular pain. I look forward to the future research that stems from this study."
Translational research aims to translate fundamental findings from basic science research into clinical practice, so that doctors of optometry can better improve patients' quality of life. Meanwhile, Dr. Ziemanski suggests doctors continue to follow the growing and evolving literature to better understand neuropathic ocular pain, in particular.
"Patients may take an interest in learning that there is an association between their eye condition and their depression," she says. "But this research area is in such an early stage that its true impact may take years to emerge."