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

## TL;DR

This study found that people with keratoconus have higher oxidative stress and lower antioxidant levels in their blood compared to those without the condition.

## Contribution

The study identifies a systemic imbalance in oxidative stress biomarkers specific to keratoconus patients.

## Key findings

- Keratoconus patients had significantly higher levels of pro-oxidant biomarkers like TOS, NOx, and MDA.
- Subjects with keratoconus showed lower levels of antioxidant markers such as TAC and thiols.
- Oxidative stress index was elevated in keratoconus patients compared to controls.

## Abstract

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.