Changes of Lacrimal Gland and Tear Inflammatory Cytokines in Thyroid-Associated Ophthalmopathy

PURPOSE. To explore changes in lacrimal gland and tear inflammatory cytokines in thyroid-associated ophthalmopathy (TAO) patients. METHODS. Patients with TAO were divided into active and inactive TAO groups. These two TAO groups and the control completed the Ocular Surface Disease Index (OSDI), underwent thorough ophthalmologic examinations, and underwent orbital magnetic resonance scan to measure the size of the lacrimal gland. Basal tears, reflex tears induced by nasal stimulation and serum samples, were collected to analyze the concentrations of interleukin (IL)-1 beta, IL-6, IL-7, IL-17A, interferon gamma, and tumor necrosis factor alpha by multiplex bead analysis. RESULTS. The coronal lacrimal gland area was significantly larger in active (P < 0.000) and inactive TAO (P = 0.002) than in the control, and the axial lacrimal gland area was significantly larger in active (P < 0.000) and inactive TAO (P = 0.001) than in the control. The coronal lacrimal gland width was significantly greater in active (P < 0.000) and inactive TAO (P = 0.001) than in the control, and axial lacrimal gland width was significantly greater in active (P < 0.000) and inactive TAO (P = 0.035) than in the control. In TAO patients, the axial area was positively correlated with IL-1 beta and IL-17A concentrations in tears (r = 0.357, P = 0.013; r = 0.359, P = 0.012), and both coronal and axial areas were positively correlated with IL-6 concentrations in tears (r = 0.346, P = 0.016; r = 0.340, P = 0.018). CONCLUSIONS. Increased inflammatory cytokines play an important role in ocular surface damages, and might be associated with the inflammatory involvement of the lacrimal gland.