目的：探讨诱导兔部分性角膜缘干细胞失代偿(limbal stem cell deficiency，LSCD)动物模型的一种新方法。

方法：分别采用C57小鼠和新西兰白兔制作完全性和部分性角膜缘干细胞失代偿动物模型。小鼠(n=30)采用1mol/L氢氧化钾溶液浸泡的滤纸片(直径3mm)置于左眼中央角膜表面30s，随后用生理盐水冲洗。白兔(n=19)切除瞬膜(第三眼睑)后，采用1mol/L氢氧化钾溶液浸泡的滤纸片(直径5mm)置于左眼颞上方角膜表面30s，随后用生理盐水冲洗。烧伤眼术后采用0.5%盐酸左氧氟沙星滴眼液4次/d。烧伤前、烧伤后第1、2、4wk，2mo采用裂隙灯显微镜观察、摄像，记录角膜溃疡、穿孔等并发症。术后2mo采用印迹细胞学检测角膜杯状细胞分布，根据裂隙灯显微镜检查所见和角膜印迹细胞学检查判断LSCD严重程度。术后2mo处死动物，角结膜切片观察角膜新生血管、杯状细胞分布。意外死亡动物不计入总数，计算并比较完全性LSCD和部分性LSCD的模型诱导成功率。

结果：30只小鼠中6只意外死亡，2只于烧伤后出现角膜穿孔，其余22只发生完全性LSCD，诱导成功率92%，烧伤后2mo小鼠角膜可见新生血管广泛分布于角膜浅层及深基质层，病理切片可见角膜新生血管。19只白兔，7只意外死亡，其余12只发生不同程度LSCD(部分性LSCD，平均累及1.17±0.39个象限)，未发生角膜穿孔情况，诱导成功率100%(P=0.543)。正常角膜区域无杯状细胞，LSCD区域角膜上皮印迹细胞学PAS染色可见杯状细胞，平均密度58.60±12.58个细胞/HP。

结论：中央角膜碱烧伤可以诱导产生完全性LSCD，部分动物会因为角膜溃疡穿孔而导致模型诱导失败，LSCD往往比较严重，且合并深层角膜新生血管。颞上方角膜碱烧伤可以诱导产生部分性LSCD，合并较少的角膜病变，角膜新生血管位于浅层。

METHODS: LSCD was induced through corneal alkali burn, C57 mice and New Zealand rabbits were used to establish the animal models. Corneal alkali burn manipulation was accomplished in experimental animals under general anesthesia combined with surface anesthesia in the operated eye. Specifically, mice(n=30)were used to induce complete LSCD model. In brief, the filter paper(diameter of 3mm)that immersed in 1mol/L potassium hydroxide solution was placed on the central corneal surface of the left eye for 30s, followed by washing with saline. In addition, rabbits(n=19)were utilized to establish the partial LSCD model. Briefly, the nictitating membrane(third eyelid)was resected, and the filter paper(diameter of 5mm)that immersed in 1mol/L potassium hydroxide solution was placed on the superior temporal peripheral corneal surface of the left for 30s, followed by washing with saline. After surgery, the model eyes were treated with 0.5% Levofloxacin Hydrochloride Eye Drops four times a day. In addition, the slit-lamp microscope was adopted for observation and photo-taking before burn, as well as at 1, 2, 4wk and 2mo after burn; meanwhile, complications such as corneal ulcer and perforation were recorded. 2mo after surgery, the corneal goblet cell distribution was detected with impression cytology, and the severity of LSCD was classified according to slit-lamp microscopic findings and corneal impression cytology. The animals were sacrificed 2mo after surgery, cornea and conjunctiva sections were made to observe angiogenesis and goblet cell distribution in cornea. Animals died accidentally were not counted into the total number, and the successful induction rates of complete LSCD and partial LSCD models were compared.

RESULTS: Six out of the 30 mice died accidentally, while 2 developed corneal perforation after burn, and the remaining 22 had developed complete LSCD only, yielding the successful induction rate of 92%. 2mo after burn, extensive angiogenesis distribution in the superficial and deep corneal stromal layers could be observed, and pathological sections revealed corneal angiogenesis. Seven out of the 19 rabbits died accidentally, while the remaining 12 had various degrees of LSCD only(partial LSCD, average involving 1.17±0.39 quadrants). Additionally, no corneal perforation was observed, and the successful induction rate was 100%. The result of Fisher's exact test P value is 0.543, without statistical difference. No goblet cells were observed in the normal corneal region, while goblet cells were observed in the LSCD region, with the average density of 58.60±12.58 cell/HP.

CONCLUSION: Central corneal alkali burn can induce complete LSCD; however, some animals will experience failure in model induction due to corneal ulcer and perforation, LSCD is generally serious and may be combined with angiogenesis in deep cornea. Alkali burn in superior temporal cornea can induce partial LSCD, which may be combined with relatively minor corneal lesion, and the corneal angiogenesis is located in the superficial layer.