Abstract
Purpose: :
The purpose of this study was to determine whether oxidative stress-related challenges cause a dysfunction in the antioxidant corneal defences in the keratoconus (KC) versus healthy corneas and that the presence of 4-hydroxy-nonenal (4-HNE), a lipid peroxidation product, may play a role in the pathogenesis of KC.
Methods: :
A total of 8 healthy and 11 ectatic corneas were studied. The research reported was conducted in compliance with "Declaration of Helsinki". Different oxidative stress-related markers were determined to asses their implication in the KC pathophysiology. Total antioxidant capacity and total nitrites present in the samples were determined. Furthermore, lipid peroxidation and glutathione contents were determined by ELISA and the presence of 4-HNE was detected by inmunohistochemistry.
Results: :
The antioxidant capacity and glutathione content in KC tissue were significantly decreased (p<0.05) when compared to healthy corneas. Moreover, the total nitrites and lipid peroxidation were significantly elevated in the corneas with KC when compared to controls (p<0.05). There was a statistically significant difference (p< 0.05) in the amount of HNE-positive cells in KC corneas when compared with healthy corneas by inmunohistochemistry.
Conclusions: :
The increased levels of oxidative stress markers and the decreased antioxidant capacity and antioxidant defences in KC corneas confirm previous data that oxidative stress is involved in the development of this disease (Buddi et al., J Histochem Cytochem 50:341-351,2002) and these results may provide new ethiopathogenic insights for the prevention and treatment of this disease in the future.
Keywords: cornea: basic science • keratoconus • oxidation/oxidative or free radical damage