冷冻伤致家兔角膜内皮损伤动物模型的建立

A study on a model of corneal endothelial injury by transcorneal freezing in rabbits

用冷冻法建立家兔角膜内皮损伤的动物模型。将直径为 8mm的铜探头置于液氮中数秒后取出 ,待探头温度显示在 - 12 0℃时将其垂直放于兔角膜中央表面分别接触 5s和 15s。结果显示冷冻区的角膜内皮细胞完全被破坏 ,内皮细胞损伤区与未损伤区之间界限清晰。冷冻 5s和 15s能造成面积相近的角膜内皮缺损 (P >0 .0 5) ,而冷冻 5s者角膜水肿较轻 (P <0 .0 5)。伤后 2 d,内皮缺损面积为(4 .13± 1.97) mm2 ,伤后 3d,一部分的角膜内皮已愈合 ,伤后 4 d所有角膜内皮缺损已被大小不一、形态不规则的再生内皮细胞所覆盖。伤后 12 d,再生的内皮细胞大小趋于均匀一致 ,为多边形。本试验通过对冷冻探头温度的统一监测 ,建立了兔角膜内皮损伤的动物模型 ,并且本模型具有可重复性及简单易行的特点。

This study is to establish a model of corneal endothelial injury by transcornel freezing.The 8 mm diameter brass probe, chilled to -120℃ with liquid nitrogen, was applied to the center of the cornea for 5 sec and 15 sec respectively;its temperature was accurately maintained with ±10℃ as recorded by the instrument while freezing the cornea.The result showed that the endothelial cells were completely absent in the area underlying the freezing.The brodeline between the area lacking endothelial cells and intact endothelial cells was very sharp.The area of endothelial wound was not significantly different between the 5 sec group and the 15 sec group (P<0.05).The thickness of central cornea in 5 sec group was significant thiner than that of 15 sec group (P<0.05).In 2 d after injury, the area of endothelial wound was(4.13±1.97)mm 2.Some of the wounds had closed completely in 3d after wounding 4 d after injury, all of the corneal wound areas were completely covered by uneven and irregular shaped endothelial cells.In 12 d after injury ,the healed endothelial cells became regular and polygonal.The results indicate that the corneal endothelial injury model by transcorneal freezing in rabbits is reproducable and standardized for the probe′s temperature was accurately maintained with (-120±10)℃ as recorded by the instrument.