Comparing Tear Film Viscosity between Sjogren and Non-Sjogren Dry Eye Disease

This study aimed to compare tear film viscosity (TFV) in Sjogren and non-Sjogren dry eye diseases (DEDs). This was a cross-sectional observational study. A total of 68 DED patients were enrolled, including 32 patients with Sjogren syndrome (SS) and 36 without SS. TFV was assessed by a tear film analyzer and determined by the momentary moving speed (MMS; MMS (t) = & alpha; x t(-& beta;), t = time (s)) with its power-law fitting-derived parameters (& alpha; and & beta;). Among the four indices of TFV (MMS (0.1 s), MMS (2.0 s), & alpha;, and & beta;), the SS-DED patients had significantly lower MMS (0.1 s) (p = 2.01 x 10(-5)), & alpha; (p = 0.0375), and & beta; (p = 0.0076). The SS-DED group also had significantly higher OSDI, lower central and nasal tear meniscus height (TMH), and higher OSS. MMS (0.1 s) was significantly correlated with nasal TMH and OSS (& rho; = 0.2520, p = 0.0381 in nasal TMH; & rho; = -0.3487, p = 0.0036 in OSS). Index & beta; was not correlated with any non-TFV tests. In conclusion, MMS (0.1 s), & alpha;, and & beta; are promising TFV indices in distinguishing SS-DED from non-SS-DED patients early. Among these TFV indices, lower MMS is the best alternative clue for detecting SS-DED.