正常角膜处于无血管状态 ,以维持角膜的透明 ,透明的角膜对眼视功能十分重要。角膜缘则具有丰富的血管网 ,在感染、外伤、免疫反应等病理情况下 ,毛细血管由角膜缘处向角膜内生长。一般认为 ,毛细血管进入角膜周边部 1～ 2mm以上即为病态 ,或称为角膜新生血管 (cornealneovascu Normal cornea in a non-vascular state, in order to maintain the corneal transparent, transparent cornea on the visual function is very important. The corneal margin is rich in vascular network, in the infection, trauma, immune response and other pathological conditions, the capillary from the corneal limbus to the corneal growth. Generally believed that the capillaries into the corneal peripheral 1 ~ 2mm or more is the pathological, or called corneal neovascularization (cornealneovascu