方法：将87只SD大鼠分为角膜缘碱烧伤20s组(A组，34只)，角膜缘碱烧伤40s组(B组，23只)，角膜中央碱烧伤40s组(C组，30只)，用浸润1mol/L氢氧化钠的滤纸片，分别烧灼大鼠角膜缘和角膜中央，术后7d裂隙灯显微镜观察角膜透明度、角膜溃疡及角膜新生血管情况，并记录上述指标。

结果：角膜缘碱烧伤(B组)较角膜中央烧伤(C组)溃疡发生率、角膜穿孔率和角膜上皮荧光素钠染色阳性率高，且有统计学差异(P<0.05)； 角膜缘烧灼时间长组(B组)溃疡发生率及角膜穿孔率高于角膜缘烧灼时间短组(A组)，且有统计学差异(P<0.05)； 烧灼角膜缘和角膜中央(A，B，C组)均能诱导出角膜新生血管。

结论：对于研究角膜新生血管的动物模型，以选择3mm圆形滤纸片角膜中央烧伤为佳； 对于研究角膜缘干细胞缺乏所致角膜病变的实验，以选择环形滤纸片放置于角膜缘20s为佳。

METHODS:The rats(n=87)were randomly divided into three groups. Corneal alkali injury was induced by placing 1mol/L NaOH soaked filter paper on the limbus of right cornea for 20 seconds(group A, n=34)or 40 seconds(group B, n=23), and on the central axis of the right cornea for 40 seconds(group C, n=30)respectively. Corneal transparency, corneal ulceration, and corneal neovascularization were observed and recorded under slit- lamp biomicroscope on day 7 post-operation.

RESULTS: Incidence of corneal ulceration, corneal perforation and positive rate of corneal fluorescein staining in limbal corneal injury groups(group A and B)were significantly higher than that of central corneal injury group(group C)(P<0.05). Incidence of corneal ulceration and corneal perforation in group B was significantly higher than group A(P<0.05). Corneal neovascularization was observed in all three groups.

CONCLUSION: Corneal alkali burns induced by 3mm diameter central cornea injury are fit for the study of corneal neovascularization, while those induced by limbus injury for 20 seconds are fit for the study on limbal stem cells deficiency.