Imbalance of Pro-Oxidant and Anti-Oxidant Biomarkers in Patients with Keratoconus.

AIM: Our study aimed to evaluate serum oxidative stress-related biomarkers (three pro-oxidants: total oxidant status (TOS), indirect assessment of nitric oxide synthesis (NOx), and malondialdehyde (MDA), and three anti-oxidants: total anti-oxidant capacity (TAC), catalase (CAT), and thiols) in patients with keratoconus (KCN).

METHODS

We conducted a single-center, cross-sectional study with the prospective enrollment of adult patients attending an outpatient ophthalmology clinic between 1 January 2024, and 1 September 2025. The diagnosis of KCN was established based on the clinical signs and two or more aberrant Pentacam parameters.

RESULTS

We evaluated 44 subjects with KCN (median age, 26 years) and 38 without KCN (median age, 28 years), with similar age and sex distributions (p-values > 0.09). All evaluated biomarkers showed statistically significant differences between subjects with KCN and those without KCN (p-values < 0.001), with higher serum TOS, NOx, MDA, CAT, and oxidative stress index levels and lower levels of TACs and thiols in subjects with KCN than in those without KCN.

CONCLUSIONS

Our findings indicate a systemic imbalance between pro-oxidant and anti-oxidant biomarkers in subjects with keratoconus.