Neutrophil-to-Lymphocyte Ratio Is Associated with the Stability of Human Corneal Endothelial Cells

Background/Objectives: Corneal endothelial cells (CEnCs) exist on the inner surface of the cornea and regulate its hydration. The immune system cannot penetrate CEnCs easily because the cornea is avascular and anterior chamber-associated immune deviation suppresses the immune reaction. Nevertheless, inflammatory cells can infiltrate through the corneal stroma and anterior chambers, and corneal endothelial inflammation can occur. In this cross-sectional study, we investigated the association between the neutrophil-to-lymphocyte ratio (NLR) and human corneal endothelial cells (CEnCs). Methods: A total of 307 eyes from 307 subjects who underwent specular microscopy were included. Corneal endothelial cell density (CECD), hexagonality (HEX), central corneal thickness (CCT), coefficient of variation (CV), and cell area were measured preoperatively using specular microscopy. Whole blood samples were obtained to measure the complete blood cell count. The NLR was calculated, and its relationship with CEnCs was evaluated. Results: In all subjects, CV was positively correlated with the percentage (%) of neutrophils (r = 0.120, p = 0.037) and absolute neutrophil count (r = 0.131, p = 0.022) and negatively correlated with the % of lymphocytes (r = -0.131, p = 0.022). HEX was correlated with the % of neutrophils (r = -0.156, p = 0.006), % of lymphocytes (r = 0.141, p = 0.014), % of basophils (r = 0.142, p = 0.013), the NLR (r = -0.129, p = 0.024), and the mean corpuscular volume (r = 0.121, p = 0.035). Conclusions: CV and HEX, which indicate the stability of CEnCs, are associated with NLR in the peripheral blood, suggesting that systemic inflammation and immunity may implicate in the pathology of CEnCs.