Biomaterial Database

Meesmann's corneal dystrophy: ultrastructural features. 1982

M Tremblay, and I Dubé

Ultrastructural studies were done on a cornea obtained at the time of lamellar keratoplasty from a patient with the clinical diagnosis of Meesmann's corneal dystrophy. Light microscopy showed in the corneal epithelium the typical tiny cysts containing cellular debris and a homogeneous substance that reacted with periodic acid and Schiff's reagent and stained with Hale's colloidal iron; as well, the basement membrane was markedly thickened. Electron microscopy revealed that the cysts had a corrugated or microvillous wall, consistent with acantholysis. The epithelial cells were rich in glycogen, and many contained the peculiar substance described by others in Meesmann's corneal dystrophy. This substance appeared to be derived from the tonofilaments and was in close relation to the desmosomes. The thick basement membrane showed secondary changes, with one thick zone that was rich in collagen fibrils mimicking abnormal anchoring fibrils and one thin zone that was poor in fibrils but had frequent intercalated fibroblasts and probably represented a repair phenomenon. There was no apparent modification of Bowman's layer or the superficial stroma.

UI	MeSH Term	Description	Entries
D008297	Male		Males
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
D010503	Periodic Acid-Schiff Reaction	A histochemical technique for staining carbohydrates. It is based on PERIODIC ACID oxidation of a substance containing adjacent hydroxyl groups. The resulting aldehydes react with Schiff reagent to form a colored product.	PAS Reaction,PAS Reactions,Periodic Acid Schiff Reaction,Periodic Acid-Schiff Reactions,Reaction, PAS,Reaction, Periodic Acid-Schiff,Reactions, PAS,Reactions, Periodic Acid-Schiff
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
D003560	Cysts	Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.	Cyst
D006003	Glycogen
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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