New Biomarkers for Patients With Fungal Keratitis From Blood Routine Examination: Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio.

Abstract

Purpose: To assess the potential of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as novel diagnostic and prognostic biomarkers in fungal keratitis (FK). Methods: This study was carried out retrospectively in 77 FK patients and 77 matched cataract controls from Henan Eye Hospital. Peripheral venous blood samples were collected via venipuncture and analyzed using complete blood count for routine clinical evaluation. FK patients were classified into three subgroups: Fusarium, Aspergillus, and Candida groups. Inflammation severity was quantified using standardized clinical scoring. The treatment modalities were used to divide the FK patients into enucleation and nonenucleation groups. Results: NLR and PLR were significantly elevated in FK versus controls (p < 0.001). NLR correlated strongly with inflammation scores (r = 0.535, p < 0.0001), exceeding PLR's moderate correlation (r = 0.311, p=0.0059). FK patients in the enucleation group had significantly higher NLR (p=0.012) and PLR (p=0.021) values than those in the nonenucleation group. There were no significant biomarker differences across fungal species (p > 0.05). Conclusion: Elevated NLR and PLR values during routine laboratory testing might serve as supplementary indicators for early suspicion of FK and monitoring inflammatory progression, particularly in resource-limited settings where specialized ophthalmic diagnostics are unavailable.