Expression And Clinical Significance Of 8-OHdG And VEGF In Primary Pterygium

Objective By detecting 8-hydroxydeoxyguanosine(8-OHd G)and vascular endothelial growth factor(VEGF)expression in primary pterygium and normal conjunctiva tissues,to investigate the oxidative DN A damage and neovascularization in the pathogenesis of primary pterygium in effect.Methods Thirty-five primary pterygium specimens and five normal conjunctival specimens which above the normal temporal bulbar conjunctiva were collected during surgery.The expression of 8-OHd G and VEGF were detected by immunohistochemistry and real-time fluorescent quantitative PCR.The results were compared with the normal conjunctival tissues.The differences and regular pattern of 8-OHd G and VEGF expression between the two groups were compared.Results 1.Expression of 8-OHd G in pterygium and conjunctival tissues There were 24(68.6%)pterygium specimens positive for 8-OHd G staining,limited to the nuclei of the epithelial layer.No substantial staining was visible in the subepithelial fibrovascular layers.All normal controls were negative for 8-OHd G staining.The difference of 8-OHd G expression between the two groups was statistically significant(P=0.007).2.Expression of VEGF in pterygium and conjunctival tissues The expression of VEGF was detected in all parts of pterygium and normal conjunctiva,and the expression level of VEGF increased gradually from pterygium head to body.The expression of VEGF in pterygium body was significantly higher than that in the head and neck(P <0.001),and also higher than that in normal conjunctiva(P=0.002<0.01).There was no significant difference of VEGF expression among head,neck and normal conjunctiva(P> 0.05).Conclusions 1.The increased levels of 8-OHd G and VEGF in the pterygium tissues indicate that oxidative DNA damage and neovascularization maybe play an important role in the pathogenesis of pterygium.2.The expression of VEGF in different parts of primary pterygium from the head to the body was gradually increased,suggesting that neovascularization of pterygium hyperplasia in the body of pterygium.