Exploring Serum Bilirubin as a Potential Biomarker for Primary Open-Angle Glaucoma

Total bilirubin (TBIL) functions as a natural antioxidant, and its levels tend to decrease with increasing oxidative stress, including in glaucoma tissue. This study aims to explore the relationship between total serum bilirubin levels and the severity of primary open-angle glaucoma (POAG). A total of 25 POAG patients and 25 control subjects further divided into aged >60 years and ≤60 years from the Glaucoma Clinic of the Universitas Sumatera Utara Hospital and its affiliated hospitals were included, consisting of 4 patients with moderate disease and 21 with advanced disease. Serum TBIL levels were measured and analyzed using the Mann-Whitney test. Results showed an average TBIL of 0.23 mg/dL in moderate cases and 0.37 mg/dL in advanced cases, with no significant relationship between TBIL and POAG severity (p=0.131). These findings indicate that total serum bilirubin levels are not related to POAG severity and are likely not a reliable clinical biomarker for glaucoma.