Circulating microRNAs as Biomarkers for Primary Open-Angle Glaucoma: A Case-Control Study

Background Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness worldwide. Early diagnosis remains challenging, highlighting the need for reliable biomarkers. In recent years, circulating microRNAs (miRNAs) have emerged as potential minimally invasive biomarkers in ocular diseases. Objective This study aimed to evaluate the expression of two selected miRNAs i.e, miR-210-3p and miR-143-3p, in plasma and aqueous humor (AH) of POAG patients, cataract patients, and healthy controls, and to assess their diagnostic potential. Methods Plasma and AH samples were collected from 30 POAG patients, 30 cataract patients, and 30 healthy controls. Small RNAs were isolated, and expression of miR-210-3p and miR-143-3p was quantified by TaqMan™ qPCR assays using miR-16-5p as an endogenous control and cel-miR-39 as an exogenous control. Data was analyzed using the 2 ^{^−ΔΔCt} method. Diagnostic accuracy was assessed by receiver operating characteristic (ROC) analysis. Results miR-210-3p expression was significantly elevated in plasma (median fold change 5.18, p < 0.0001) and AH (median fold change 2.81, p = 0.0003) of POAG patients compared with cataract and normal controls. Plasma ROC analysis for miR-210-3p yielded an AUC of 0.862 (95% CI: 0.751–0.936), with 86.2% sensitivity and 87.9% specificity. In contrast, miR-143-3p was significantly upregulated only in AH of POAG patients (median fold change 8.24, p < 0.0001), but not in plasma. Plasma ROC analysis for miR-143-3p showed poor diagnostic performance (AUC = 0.597, p = 0.20). Conclusion miR-210-3p is consistently elevated in both plasma and aqueous humor of POAG patients, supporting its potential as a minimally invasive diagnostic biomarker. miR-143-3p shows ocular-specific upregulation and may provide complementary information on local disease mechanisms. Larger multicenter studies are warranted to validate these findings and explore their clinical utility in early POAG detection.