Diagnostic value of tear Galectin-1 and Galectin-3 in keratoconus: a prospective case-control study

This study aims to evaluate tear Galectin-1 and Galectin-3 levels in patients with keratoconus and healthy controls, assess their diagnostic performance, and investigate their associations with corneal tomography parameters. This prospective case–control study included 40 eyes of 40 patients with keratoconus and 33 eyes of 33 healthy controls. All participants underwent a comprehensive ophthalmic examination and corneal tomographic assessment using a Scheimpflug imaging system. Tear samples were collected using Schirmer strips, and Galectin-1 and Galectin-3 concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic performance of Galectin-1 and Galectin-3 to discriminate between keratoconus and healthy controls, and correlation analyses were performed to explore the relationships between galectin levels and corneal tomographic parameters. The keratoconus and control groups were comparable in terms of age, sex distribution, and tear sample volume (all p > 0.05). Tear Galectin-1 and Galectin-3 levels were significantly higher in the keratoconus group than in controls (1033 ± 570 vs. 617 ± 172 pg/mL, p = 0.006; and 16.4 ± 5.4 vs. 7.1 ± 4.7 ng/mL, p < 0.001, respectively). ROC analysis demonstrated AUC values of 0.687 for Galectin-1 and 0.899 for Galectin-3. At a cut-off value of 10.93 ng/mL, Galectin-3 showed a sensitivity of 87.5% and a specificity of 78.8% for discriminating keratoconus from healthy controls. When correlation analyses were performed exclusively within the keratoconus group, no significant correlations were observed between galectin levels and corneal tomographic parameters. Tear Galectin-1 and Galectin-3 levels were significantly elevated in patients with keratoconus compared with healthy controls. Among the two galectins, Galectin-3 demonstrated superior diagnostic performance, supporting further investigation of Galectin-3 as a potential biomarker for keratoconus.