Experimental study of the expression of interleukin-6,tumor necrosis factor-α and intercellular adhesion molecular-1 on evaporative dry eye in the rabbit

Objective To investigate the role of inflammatory cytokine in evaporative dry eye.Methods Twenty rabbits were randomly divided into an experimental group and a control group.A dry eye model was established by cauterizing the meibomian gland orifices of rabbits in the experimental group.ELISA and radioimmunity were used to detect the concentrations of interleukin-6(IL6) and tumor necrosis factor-alpha(TNF-α) in tears at 1,6,and 11 weeks after cauterizing the meibomian gland.The rabbits were sacrificed 11 weeks after cauterizing the meibomian gland.Their corneal and conjunctival epithelia were examined by immunohistochemical staining to detect the expression of intercellular adhesion molecular-1(ICAM-1).Results Schirmer Ⅰ test wetting in the experimental group(5.1±1.6)mm was significantly shorter than that of the control group(18.6±4.2)mm at 6 weeks after cauterizing(P 0.01).BUT time in the experimental group(3.4±1.1)s was shorter than that of the control group(17.6±3.4)s(P0.01).The concentration of IL-6 in tears was higher in the experimental group(434.4±38.7)pg/ml than in the control group(150.1 ±23.6)pg/ml(P0.01).The concentration of TNF-α in tears was higher in the experimental group(7.63 ±0.40)pg/ml than in the control group(3.53±0.54)pg/ml(P0.01).ICAM-1 expression in positive cells of 1000 cells in the corneal and conjunctival epithelia in the experimental group(272.1±46.8,302.7±56.3,respectively) was stronger than that of the control group(50.2±5.9,60.4±15.3,respectively)(P 0.01).Conclusion Cytokines play an important role in the pathogenesis of evaporative dry eye.