Oxidative stress in corneal limbal rings

Abstract

Abstract Purpose The aim of this work was to study oxidative stress markers in corneal limbal rings stored in Optisol at different preservation times. Methods Total Antioxidant capacity was measured with a commercial kit (Antioxidant Assay Kit, Cayman). Total nitrites were measured with a commercial kit where the amount of total nitrites was monitored spectofotometrically by reading the absorbance at 540 nm. Moreover, HNE (4‐hydroxy‐2‐nonenal) immunohistoquemistry was performed at 3 µm thick paraffin sections. Results The antioxidant capacity in corneal limbal rings preserved for 7 days were decreased significantly (0.5 ± 0.02 mM/mg prot) when compared to a fresh corneal limbal ring (1.1 ± 0.28 mM/mg prot) * p< 0.05. Moreover, the total nitrites were significantly elevated in corneal limbal rings preserved for 7 days (1.47 ± 0.18 umol/L/mg prot) when compared to fresh corneal limbal rings ( 0.89 ± 0.46 umol/L/mg prot) * p< 0.05. Immunohistoquemistry revealed that there exist an increase in HNE positive cells as conservation time increases. Conclusion Oxidative stress factors increases with time in corneal limbal rings preserved in Optisol.