药物向眼内的通透,在眼科临床上及实验研究上都是很重要的问题。期待一种药物对眼组织起到作用,药物必须首先向眼内通透。此通透并非只靠扩散作用,而要经过几道屏障,如视网膜、睫状体、虹膜,它们是具有选择性的只允许某种物质通过,而另外一些则不能。甚至眼还有从眼内向眼外通透的逆向运输系统存在。作为局部投药方法之一的点眼法,其药液要经过几道屏障才能到达前房。如角膜前的泪膜层,角膜的多层上皮,继之有角膜实质层及内皮细胞层。眼药液首先与泪液接触并与之混合,其一部分经角膜各层而到达前房,即此间需经过几道屏障。但结膜囊内的容量究竟有限,超过这个量则点入眼内的药液便溢出眼外。又每当瞬目时,点眼的药液就与泪液一道经过泪小管、泪囊、鼻泪管流出,因 The penetration of drugs into the eye is a very important issue in both clinical and experimental research in ophthalmology. Looking forward to a drug on the role of eye tissue, the drug must first be permeable to the eye. This permeation does not rely solely on diffusion, but rather on a few barriers such as the retina, ciliary body, iris, which are selective and allow only certain substances to pass through while others do not. Even the eye and reverse osmosis from the eye to the eye of the existence of the transport system. As one of the local administration of point eye method, the liquid to go through several barriers to reach the anterior chamber. Such as the pre-corneal tear film, multi-layer corneal epithelium, followed by corneal parenchymal and endothelial cell layer. The eye drops first come in contact with and mix with tear fluid, and a portion of it reaches the anterior chamber across the corneal layers, requiring several barriers between them. However, the capacity of the conjunctival sac is limited, more than this amount is injected into the eye liquid will overflow the eye. And when the blink of an eye, eye drops of liquid and tear through a canal, lacrimal sac, nasolacrimal duct outflow due to