Dry Eye Linked to Chronic Overlapping Pain in Veteran Population

There may be a correlation between dry eye (DE) and chronic pain in the US military veteran population.

In a retrospective review of Florida veterans medical records between 2010 and 2014, researchers found a correlation between severity DE symptoms and non-ocular pain. They also found that individuals with chronic overlapping pain conditions (COPC) had more severe DE symptoms, but similar ocular surface signs.

The study, led by Charity J. Lee, from the Miami Veterans Administration Medical Center and Bascom Palmer Eye Institute at the University of Miami, was presented at the 121st Annual Meeting of the American Academy of Ophthalmology (AAO 2017) in New Orleans, LA.

Chronic pain, as defined by the researchers as a pain that persists beyond expected resolution — or about 3 months — is prevalent in 116 million US adults.

Lee explained that COPC is common among non-ocular conditions, including back pain, migraines, and fibromyalgia. With DE, a multifactorial disease that affects about 15% of US citizens, the same is held in a veteran population.

Of the approximate 3.2 million patients seen at Veterans Affairs (VA) hospitals between the studied years, DE was diagnosed in 959,881 (29.4%) patients. Another 854,480 (26.2%) were diagnosed with tear film dysfunction (TFD), and 186,299 (5.7%) were diagnosed with ocular pain. Less than 3% of patients had the latter 2 diagnoses together, Lee said.

In patients with TFD, researchers found an increased frequency of diagnoses with age. The average TFD patient age at the time of diagnosis was 69.4 years old, while ocular pain patients were 63.4.

Researchers also found that patients were more likely to be diagnosed with DE with the greater rate of chronic pain condition diagnoses. The 422 patients diagnosed with 13 or more chronic pain conditions had at least an 80% chance of being diagnosed with DE as well.

Ocular pain was most strongly associated with headaches, tension headaches, migraines, temporomandibular joint disorders, pelvic pain, central pain syndrome, and firbomyalgia in the veteran patient population, Lee said. The frequency of association for these conditions ranged from 2.98% to 2.23% (p<0.0005).

Because the study relied on International Classification of Diseases’ Ninth Revision (ICD-9), Lee and researchers could confirm diagnoses nor capture the full complexity of patients’ DE diagnoses. That said, they were able to confirm correlations between ocular pain and COPC diagnoses, and TFD and non-COPC diagnoses.

Lee prosed that sensations of dryness in some patients could be a local manifestation of system-wide diagnosis of chronic pain. She also noted there are few treatment options for DE and multi-disciplinary care patients.

Panel members at AAO 2017 suggested the next course of research focus on possibly using systemic treatment for DE and COPC. Though the study did not fully address patient treatment measures, Lee agreed it’s a worthwhile hypothesis.

“Since they tend to coexist together, I think that broad treatment may definitely have an effect, not only with dry eye, but with the rest of the pain conditions that come along with it,” Lee said.