Increased Systemic Immune-Inflammation Index Levels in Patients with Dry Eye Disease.

PURPOSE To evaluate the systemic immune-inflammation index (SII) levels, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) in patients with dry eye disease (DED) and to compare with control subjects. METHODS This prospective study included 47 DED patients and 47 age- and sex-matched healthy controls. Ophthalmological examination, diagnostic DED tests, and routine complete blood cell count parameters were analyzed. The SII value was calculated as follows: platelet count × (neutrophil/lymphocyte). RESULTS The mean SII, NLR, and PLR levels were significantly higher in DED patients compared to controls (p < .001, p < .001 and p = .009, respectively). Using the receiver operating characteristics (ROC) curve analysis to predict patients with DED, the highest area under the curve (AUC) was determined SII (0.761 for SII, 0.727 for NLR, and 0.653 for PLR). CONCLUSIONS As a novel tool superior to other inflammatory markers, SII may be a cheap and reliable indicator of inflammatory status in DED patients.