Assesment of oxidative stress and antioxidant status in pseudoexfoliation syndrome with ocular and systemic comorbidities

This study aimed to investigate oxidative stress (OS) markers and thiol-disulfide homeostasis (TDH) in patients with pseudoexfoliation (PEX) syndrome and to investigate their associations with ocular and systemic comorbidities.

This case-control study included 89 participants, comprising 45 patients with PEX and 44 age- and sex-matched controls. Serum oxidative stress parameters, including total thiol (TT), native thiol (NT), disulfide, thiol-disulfide ratios, total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI), were measured and compared between groups. The diagnostic utility of OS biomarkers was assessed through receiver operating characteristic curve (ROC) analysis. Additionally, the interrelationships among these biomarkers and their associations with ocular and systemic comorbid conditions observed in PEX were examined.

TT and NT levels were significantly higher in PEX patients whereas disulfide, disulfide/TT, disulfide /NT and TAS were significantly lower. PEX patients revealed a 1.18‑fold increased risk of glaucoma with elevated disulfide and a 1.61‑times increased risk of hypertension with elevated disulfide levels. ROC evaluation demonstrated a high level of diagnostic capability: TT (AUC = 0.808, cut-off 416 µmol/L, sensitivity 69%, specificity 86%), NT (AUC = 0.827, cut-off 377 µmol/L, sensitivity 67%, specificity 91%), and disulfide (AUC = 0.681, cut-off 23.5 µmol/L, sensitivity 80%, specificity 52%).

Although our study shows that thiol-disulfide homeostasis appears to be significantly associated with glaucoma and hypertension in PEX patients, this relationship is not equally distributed across all comorbid conditions examined, and oxidative imbalance plays a more selective role in the disease burden associated with PEX.