光学相干断层扫描血管造影（OCTA）在异种角膜移植供体选择中的应用研究

目的　利用光学相干断层扫描血管造影（optical coherence tomography angiography，OCTA）技术比较新西兰兔和猫角膜上皮、角膜全层厚度与人类的差别，探讨不同动物作为异种角膜移植实验模型的形态学依据。方法　雄性新西兰白兔和雄性猫各12只，分为A、B两组，每组各12只，OCTA技术测量每组样本双眼角膜上皮和角膜全层的厚度，所得数据以瞳孔为中心，根据距离角膜中央区的距离不同，利用系统软件将角膜划分为17个区域。中央区角膜是角膜正中间直径为2 mm的区域，内环和外环直径分别是5 mm和6 mm。在内外环分别又分出八个区域:上方（S）、鼻上（SN）、鼻侧（N）、鼻下（IN）、下方（I）、颞下（IT）、颞侧（T）、颞上（ST），测量各区域角膜上皮和角膜全层厚度。比较新西兰兔和猫角膜上皮、角膜全层厚度与人类的差别。结果　猫角膜上皮和角膜全层厚度均大于兔。角膜厚度:猫角膜全层是中央薄、周边厚，其中在T5、ST5、S5、SN5、N5区与中央区的厚度差异均有统计学意义（均为P＜0.05），角膜上皮在ST5、S5、SN5区与中央区厚度的差异均有统计学意义（均为P＜0.05）；兔角膜全层同样为中央薄、边缘厚，其中在T5、IT5、IN5、N5、T6、N6区与中央区厚度差异均有统计学意义（均为P＜0.05），角膜上皮ST5、S5、SN5、ST6、S6、SN6区与中央区厚度差异均有统计学意义（均为P＜0.05）。与人类角膜相比，两种实验动物与人在角膜全层和角膜上皮厚度方面差异均有统计学意义（均为P＜0.05）。结论　猫角膜与人类角膜在角膜全层厚度和角膜上皮厚度及其分布方面具有相似的区域，同时，猫角膜全层厚度和角膜上皮厚度均较人类厚，这在异种角膜移植后的屈光调节中也具有优势。猫较兔更适合作为人类异种角膜移植的潜在供体。

Application of optical coherence tomography angiography in donor selection in xenocorneal transplantation

Objective　To compare the thickness of corneal epithelium and full-thickness of the cornea among New Zealand rabbits，cats and the human using optical coherence tomography angiography (OCTA) technology as to explore the morphological basis for different animals as experimental models of xenocorneal transplantation.Methods　Totally selected 12 New Zealand male rabbits and 12 male cats were included in this study and divided into group A and B.Then the thickness of corneal epithelium and full-thickness of the cornea of both eyes in the two groups were measured with OCTA technology，and according to the distance from the center of the cornea，the cornea was divided into 17 areas by System software.The center of the cornea was a diameter of 2 mm around the center of the cornea，with the inner ring and outer ring of 5 mm and 6 mm in diameter，respectively；and the inner and outer ring region was again divided into 8 areas，including superior side (S)，superior nose side (SN)，nasal side (N)，inferior nose side (IN)，inferior side (I)，inferior temporal side (IT)，temporal side (T)，superior temporal side (ST).Then the thickness of corneal epithelium and full-thickness of the cornea in each region were measured for comparing the difference of New Zealand rabbits’ and cats’ corneal thickness with the human’s.Results　The thickness of corneal epithelium and full-thickness of the cornea of cats were both thicker than those of rabbits.The full-thickness of the cats’ cornea became thinner from the central to the peripheral side，and the difference of thickness between the T5，ST5，S5，SN5，N5 areas and the central of the cornea was statistically significant (all P<0.05)；the thickness of corneal epithelium in the ST5，S5，SN5 areas was significantly thicker than the central area (all P<0.05)；And this was true of the rabbits’ full-thickness of the cornea，and the difference in the full-thickness of the cornea between the T5，IT5，IN5，N5，T6，N6 area and the central region was statistically significant (all P<0.05)；meanwhile there were also significant difference in the thickness of corneal epithelium between the ST5，S5，SN5，ST6，S6，SN6 areas and the central area (all P<0.05).Additionally，there were significant differences in the thickness of corneal epithelium and full-thickness of the cornea between the two experimental animals and humans (all P<0.05).Conclusion　The cornea of cats possesses similar regions in corneal full-thickness and epithelial thickness as well as the distribution to human cornea，so cats have superiority to the rabbits for the potential donor of xenocorneal transplantation in human beings.