Biomaterial Database

Contributions of electron microscopy to the study of corneal pathology. 1976

F M Polack

Most of the electron microscopic studies of pathological corneas have been done only recently. Keratoplasty has been the most important source of specimens for ultramicroscopic investigation. With the introduction of electron microscopic techniques, we have been able to confirm many light microscopic studies in pathological corneas. This contribution has been most valuable in the identification of the sites and types of pathological changes in corneal dystrophies and degenerations. This review of electron microscopic studies describes the present concepts on the nature of the histological changes in dystrophies and degenerations of the anterior and posterior corneal layers and corneal stroma. It also includes a review of some corneal inflammatory conditions as well as metabolic disorders affecting its transparency.

UI	MeSH Term	Description	Entries
D007635	Keratitis, Dendritic	A form of herpetic keratitis characterized by the formation of small vesicles which break down and coalesce to form recurring dendritic ulcers, characteristically irregular, linear, branching, and ending in knoblike extremities. (Dictionary of Visual Science, 3d ed)	Furrow Keratitis,Keratitis, Furrow,Dendritic Keratitides,Dendritic Keratitis,Furrow Keratitides,Keratitides, Dendritic,Keratitides, Furrow
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
D008266	Macula Lutea	An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. (From Cline et al., Dictionary of Visual Science, 4th ed)	Lutea, Macula,Luteas, Macula,Macula Luteas
D008268	Macular Degeneration	Degenerative changes in the RETINA usually of older adults which results in a loss of vision in the center of the visual field (the MACULA LUTEA) because of damage to the retina. It occurs in dry and wet forms.	Maculopathy,Maculopathy, Age-Related,Age-Related Macular Degeneration,Age-Related Maculopathies,Age-Related Maculopathy,Macular Degeneration, Age-Related,Macular Dystrophy,Maculopathies, Age-Related,Age Related Macular Degeneration,Age Related Maculopathies,Age Related Maculopathy,Age-Related Macular Degenerations,Degeneration, Macular,Dystrophy, Macular,Macular Degeneration, Age Related,Macular Degenerations,Macular Dystrophies,Maculopathies,Maculopathy, Age Related
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
D002114	Calcinosis	Pathologic deposition of calcium salts in tissues.	Calcification, Pathologic,Calcinosis, Tumoral,Microcalcification,Microcalcinosis,Pathologic Calcification,Calcinoses,Calcinoses, Tumoral,Microcalcifications,Microcalcinoses,Tumoral Calcinoses,Tumoral Calcinosis
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
D003316	Corneal Diseases	Diseases of the cornea.	Corneal Disease,Disease, Corneal,Diseases, Corneal
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
D003318	Corneal Opacity	Disorder occurring in the central or peripheral area of the cornea. The usual degree of transparency becomes relatively opaque.	Leukoma,Corneal Opacities,Leukomas,Opacities, Corneal,Opacity, Corneal