Dry eye disease (DED) and other pain disorders occur more frequently in patients with traumatic brain injury (TBI), suggesting a shared pathophysiology, a recent study found.1 Researchers retrospectively reviewed the charts of all US veterans seen in a Veterans Administration hospital between January 2010 and December 2014 to determine the prevalence of DED and comorbidities. They then compared results between those with and without a diagnosis of TBI.

Evaluating records on over 3.2 million veterans revealed that patients with a TBI diagnosis were more likely to also have a DED diagnosis than those without TBI. Those with TBI were also twice as likely to suffer from chronic pain, headache, depression or post-traumatic stress disorder. Analysis showed that “central pain syndrome, cluster headache, sicca syndrome, keratoconjunctivitis sicca and late effect of injury to the nervous system (as can be seen after TBI) were all closely clustered together,” the study says.

These results were significant enough for the researchers to conclude that “DED and pain disorders occur at higher frequencies in patients with a diagnosis of TBI, suggesting a common underlying pathophysiology.”

An earlier report on the same retrospective review found dry eye comorbid with other chronic pain syndromes.2 Among the total population studied, 29.4% experienced dry eye. Disease frequency increased with the number of pain conditions reported, the study found. Ocular pain was most strongly associated with headache, temporomandibular joint dysfunction, pelvic pain, central pain syndrome and fibromyalgia/muscle pain. Tear film dysfunction was most closely associated with osteoarthritis and postherpetic neuralgia.

1. Lee CJ, Felix ER, Levitt RC, et al. Traumatic brain injury, dry eye and comorbid pain diagnoses in US veterans. Br J Ophthalmol. 2018;102(5). [Epub ahead of print].
2. Charity CJ, Levitt RC, Felix ER, Sarantopoulos CD, Galor A. Evidence that dry eye is a comorbid pain condition in a U.S. veteran population.Pain Reports: Nov/Dec 2017;2(6):629.