Biomaterial Database

The basement membrane complex of the human corneal epithelium. 1981

H Brewitt, and E Reale

The present report reviews the fine structure of the basement membrane zone or complex in the normal human cornea and describes its alterations in cases of early and acute keratoconus. In normal human cornea the basement membrane zone is formed by a basal lamina (with a lamina lucida and a lamina densa), "special fibrils", collagen fibrils and assemblies of filaments. These components are less evident in the central region of the cornea than in its periphery. In early stages of keratoconus the basement membrane zone is thickened and the lamina densa displays an irregular course. In acute keratoconus, the basement membrane zone is also thickened and includes a large number of "special fibrils" as well as bundles of "microfibrils" (oxytalan fibers). The conclusion that the basement membrane complex of the corneal epithelium is equivalent to the epidermal-dermal junction of the skin is discussed.

UI	MeSH Term	Description	Entries
D007640	Keratoconus	A noninflammatory, usually bilateral protrusion and thinning of the CORNEA, the apex being displaced downward and nasally. It occurs most commonly in females at about puberty. Two closely related noninflammatory corneal ectasias are pellucid marginal degeneration and keratoglobus.	Keratoglobus,Pellucid Marginal Corneal Degeneration,Pellucid Marginal Degeneration,Degeneration, Pellucid Marginal,Marginal Degeneration, Pellucid,Pellucid Marginal Degenerations
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D003315	Cornea	The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)	Corneas
D003317	Corneal Dystrophies, Hereditary	Bilateral hereditary disorders of the cornea, usually autosomal dominant, which may be present at birth but more frequently develop during adolescence and progress slowly throughout life. Central macular dystrophy is transmitted as an autosomal recessive defect.	Corneal Dystrophies,Granular Dystrophy, Corneal,Groenouw's Dystrophies,Macular Dystrophy, Corneal,Stromal Dystrophies, Corneal,Corneal Dystrophy,Corneal Dystrophy, Hereditary,Corneal Granular Dystrophies,Corneal Granular Dystrophy,Corneal Macular Dystrophies,Corneal Macular Dystrophy,Corneal Stromal Dystrophies,Corneal Stromal Dystrophy,Dystrophy, Corneal,Dystrophy, Corneal Granular,Dystrophy, Corneal Macular,Dystrophy, Corneal Stromal,Dystrophy, Hereditary Corneal,Groenouw Dystrophies,Groenouws Dystrophies,Hereditary Corneal Dystrophies,Hereditary Corneal Dystrophy,Stromal Dystrophy, Corneal
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D001485	Basement Membrane	A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.	Basal Lamina,Basement Lamina,Lamina Densa,Lamina Lucida,Lamina Reticularis,Basement Membranes,Densas, Lamina,Lamina, Basal,Lamina, Basement,Lucida, Lamina,Membrane, Basement,Membranes, Basement,Reticularis, Lamina