严重兔角膜碱烧伤的电子显微镜观察——上皮和基质的修复

The Electron Microscopical Observation of Severe Alkali-burned Rabbit Corneas: Epithelial and Stromal Repair

光、电镜下观察36只兔角膜碱烧伤上皮和基质的变化。结果细胞迅速死亡,但胶原形态正常。上皮修复始于伤后8小时,一般4天愈合,5至7天新生上皮重新脱落。基质伤典型病理改变为大量多形核自细胞无菌性浸润。浸润区板层结构紊乱,胶原纤维由一些无周期的细纤维状物代替,或被溶解消化,其中有类似溶酶体颗粒,提示角膜溃疡主要系白细胞浸润所致。成纤维细胞和角膜新生血管促进基质修复。

The epithelia and stromas of experimentally alkali-burned corneas of 36 rabbits were studied by light and electron microseopy. The direct action of alkali causes the rapid death of all cellular components, but the collagen lamellae were morphologically normal. The epithelial regrowth started at 8 hours following the burn, and ususally healed by day 4. The epithelial defects occurred again from day 5 to 7. The prominent feature of the alkali-burned corneas is sterile infiltration of numerous polymorphonuclear leukocytes (PMNs) into the stroma. The collagen lamellae were disarranged around the PMNs. Electron dense granular material, possible lysosomes, was found extracellularly adjacent to the PMNs. These findings strongly suggested that the infiltrating PMNs play a primary role in the stromal ulceration of alkali-burned corneas. The importance of fibroblasts and neovascularization in promoting the stromal repair is also discussed in this article.