糖皮质激素对真菌性角膜炎的影响

目的探讨糖皮质激素对真菌性角膜炎（MK）的影响。方法C57BL／6小鼠分别制作茄病镰刀菌角膜炎及烟曲霉菌角膜炎模型各112只，20只小鼠为对照组。接种后连续3d各取56只给予地塞米松滴眼液点眼，观察不同时期应用地塞米松组眼部表现及病理检查与未用药组、对照组的差别。结果应用地塞米松小鼠病程延长，接种后2周内真菌性角膜炎表现比未用药组严重，差异有统计学意义（P〈0．05），病理检查显示角膜中病原菌负荷量及其侵袭力增加（P〈0．05）。结论糖皮质激素通过增加真菌繁殖力及侵袭力，延长组织修复周期，加重病情延长病程。

Effect of corticosteroid on the pathogenesis of mycotic keratitis

ObjectiveThe widespread application of corticosteroid is one of the most important factors resulting in the increase of mycotic keratitis,and the pathogenic mechanism of corticosteroid influencing the mycotic keratitis is fairly complicate.The aim of this paper was to investigate the influence of corticosteroid on mycotic keratitis.MethodsThe animal models of mycotic keratitis were established by corneal scarification with strain.244 mice were randomly divided into 4 experimental groups and 1 blank group and 56 mice for each experimental group and 20 mice in blank group.Fusarium solaui (FS) were inoculated on the mice in the group 1 and group 2 and aspergillus fumifutus(AF) were inoculated in group 3 and group 4,and physiological saline (PS) for the blank group.Group 2,group 4 and the blank group were treated with dexamethasone drops for 3 days after inoculation,and the influence of corticosteroid on mycotic keratitis were observed at 2,4,8 and 14 days after infection.ResultsOn the clinical scoring of mycotic keratitis,the inflammatory reaction was more serious and more numbers of pathogens were found in the mice corneas in group 2 and group 4 compared with group 1 and group 3 with curse of disease (P<0.05).At the 14 th day,the numbers of pathogens in corneas in group 1 and group 3 were obviously decreased,and more new vessels could be seen.However,on the mice cornea in the group 2 and group 4,more pathogens and fewer new vessels only in limbus were found.Large quantity of mycelial penetrated corneal endothelium and entered anterior chamber.The loading numbers and invasiveness of mycetes in corneas were significant enhanced in group 2 and group 4(P<0.05).ConclusionCorticosteroid promotes the inflammatory reaction of fungal keratitis by increasing invasive power and productivity of mycetes,suppressing local immunity and delaying tissue repairing cycle.