MATR3 (AUC = 0.95), CXCL9 (AUC = 0.95), and KCNA3 (AUC = 0.90) were among the best candidate markers for viral keratitis, and S100A8 (AUC = 1), CXCL8 (AUC = 1), and CCL20 (AUC = 1) were among the best candidates for bacterial/fungal keratitis. This evidence concerns the gene CCL20 and fungal keratitis.