Congential nasolacrimal duct obstruction: investigating the role of systemic inflammation through novel biomakers.

Objective: Congenital nasolacrimal duct obstruction (CNLDO) is a common lacrimal system anomaly in newborns and infants. We aimed to evaluate the role of inflammation in the pathogenesis of persistent CNLDO and its potential use in diagnosis and follow up, focusing on novel inflammatory biomarkers: Systemic Immune-Inflammation Index (SII), Neutrophil-to-lymphocyte ratio (NLR), Platelet-to-lymphocyte ratio (PLR), Red cell distribution width (RDW), and Mean platelet volume (MPV).

Methods: A retrospective case-control study involving 76 CNLDO patients and 47 age-matched healthy controls was conducted. Complete blood count parameters were analyzed to calculate SII, NLR, PLR, RDW, and MPV. Receiver Operating Characteristic (ROC) analysis determined the diagnostic efficacy of these markers.

Results: SII, RDW, and neutrophil count were significantly elevated in the CNLDO group (p < 0.05). An elevated SII (cutoff > 200.9) demonstrated a sensitivity of 63.2% and a specificity of 63.8%. ROC analysis (AUC = 61.7%, p = 0.029) indicated that SII is a more significant marker for diagnosing CNLDO compared to NLR and PLR.

Conclusion: Elevated SII, indicative of systemic inflammation may serve as a significant biomarker in the diagnosis of CNLDO that does not resolve spontaneously and requires probing. SII > 200.9 acts as a threshold that aids in the diagnosis of persistent CNLDO. Being a valuable biomarker, SII can be used in monitoring patients with CNLDO and in identifying those who will require advanced treatment like probing. Prospective studies are essential to validate these findings.