Evaluation of tear osmolarity and tear function in patients with Behçet's syndrome.

Objective: To evaluate the effects of Behçet's syndrome (BS) on tear osmolarity and tear film function tests.

Methods: Thirty patients with BS and 41 control subjects were enrolled in this study. Tear osmolarity was measured with an osmometer. Tear film function tests involved corneal fluorescein staining, tear film breakup time (TBUT), Schirmer's 1 test, and an Ocular Surface Disease Index (OSDI) Questionnaire.

Results: The patients with BS had significantly higher tear osmolarity (p = 0.000) and OSDI scores (p = 0.000) than the healthy controls. The TBUT (p = 0.000) and Schirmer's 1 test (p = 0.033) results were significantly lower in the BS group, but the fluorescein staining results were not statistically different. A significant correlation was found between tear osmolarity, OSDI, and the activity of BS.

Conclusions: BS is associated with hyperosmolarity of the tear film, which can damage the ocular surface and affect tear functions.