id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-022363-1l887fyy	nan	Cornea	2008-11-10		.txt	text/plain	9349	474	38	The major attribute of cornea is its clarity, and it is the loss of clarity that is the most obvious indicator of corneal disease.The clarity results from several highly specialized anatomic and physiologic features: an unusually regular, nonkeratinized and nonpigmented surface epithelium; an avascular, cell-poor stroma composed of very thin collagen (mostly type I) fibrils arranged in orderly lamellae separated by a critical distance to allow the uninterrupted passage of light (620-640 Angstroms); and a high degree ofstromal dehydration maintained by the presence of epithelial tight junctions, endothelial tight junctions, and a Na-K-dependent ATP-ase pump in the cell membrane of the corneal endothelium ( Fig. 4.25A) . Regardless of cause, corneal inflammation initially follows the stereotyped sequence of edema and leukocyte immigration from tears and distant limbic venules.With severe lesions, corneal stromal vascularization, fibrosis and epithelial metaplasia with pigmentation may occur.	./cache/cord-022363-1l887fyy.txt	./txt/cord-022363-1l887fyy.txt