corneal epithelium


Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Related to corneal epithelium: Corneal endothelium, Corneal stroma, Bowman's membrane

corneal epithelium

The thin, layered, outer ‘skin’ of the cornea. Advances in cell culture techniques have made it possible to grow complete sheets of viable corneal epithelium from a tiny sample taken from the edge of the patient's cornea. This is an important advance in the management of conditions featuring corneal epithelial disorders.

corneal epithelium 

The outermost layer of the cornea consisting of stratified epithelium mounted on a basement membrane. It is made up of various types of cells; next to the basement membrane are the basal cells (columnar in shape), then two or three rows of wing cells and near the surface are two or three layers of thin surface squamous cells (or superficial cells). The outer surfaces of the squamous cells have projections (called microvilli and microplicae), which extend into the mucin layer of the precorneal tear film and are presumed to help retain the tear film. The epithelium in humans has a thickness of about 51 μm. Some dendritic cells of mesodermal origin are also normally present. Epithelial stem cells are located at the limbus; they give rise to the basal cells. The corneal epithelium receives its innervation from the conjunctival and the stromal nerves. The life cycle of epithelial cells is about a week (Fig. C20). See Langerhans' cell; epikeratoplasty; mitosis; pachometer; palisades of Vogt.
Fig. C20 Diagram showing the various layers of the corneal epitheliumenlarge picture
Fig. C20 Diagram showing the various layers of the corneal epithelium

epithelium

pl. epithelia [Gr.] the cellular covering of internal and external surfaces of the body, including the lining of vessels and other small cavities. It consists of cells joined by small amounts of cementing substances. Epithelium is classified into types on the basis of the number of layers deep and the shape of the superficial cells. Standard classifications include ciliated (cilia attached), columnar (taller than wide), cuboidal (same height as width), pseudostratified (single layer but because of varying cell height appears to be more than one), simple (one cell layer), squamous (flattened, plate-like cells), stratified (more than one layer), transitional (variable number of layers apparent). Other types are listed below.

anterior epithelium
the thin layer of stratified squamous cells that form the outermost layer of the cornea.
corneal epithelium
see anterior epithelium (above).
germinal epithelium
thickened peritoneal epithelium covering the gonad from earliest development; formerly thought to give rise to germ cells.
glandular epithelium
that composed of secreting cells.
lens epithelium
cuboidal epithelium covering the lens.
pigmentary epithelium, pigmented epithelium
that made of cells containing granules of pigment.
posterior epithelium
the single layer of epithelial cells on the back of the cornea, between stroma and aqueous humour; the corneal endothelium.
retinal pigment epithelium
see retina.
sense epithelium, sensory epithelium
References in periodicals archive ?
Safflower extract and aceglutamide injection promoting the repair of nerve fibers after the corneal epithelium injury
Successful regrafting of cultivated corneal epithelium using amniotic membrane as a carrier in severe ocular surface disease.
To our knowledge, this is the first paper investigating the effects of bone marrow MSCs (BM-MSCs), adipose tissue MSCs (Ad-MSCs), or corneal limbal epithelial stem cells (LSCs) on the antioxidant protective mechanism in the regenerated corneal epithelium and on corneal optical properties evaluated by central corneal thickness (taken as an index of corneal hydration) and corneal transparency.
There are other factors contributing to the keratopathy such as a poorly differentiated corneal epithelium, abnormal cellular adhesions, impaired response to lesions, and corneal conjunctival infiltration, all contributing to an impaired environmental surrounding of the corneal limbus [1].
The so-called KID (keratitis, ichthyosis, deafness) syndrome is a congenital disorder of ectoderm that affects not only the epidermis, but also other ectodermal tissues such as the corneal epithelium and the inner ear.
There was conjunctival injection and bilateral diffuse staining of the corneal epithelium, within the boundaries of the LASIK flaps (Figs.
Therefore, sources of autologous tissue that can functionally replace the corneal epithelium have been considered as an alternative to allogenous limbal transplants.
Each transplanted lens restored healthy corneal epithelium, reduced pain, and improved vision when measured at 8 to 13 months.
986 an engineer, Munnerlyn, who had been studying about the direct reshaping of cornea's central optical zone using tissue ablation on an extensive area, coined the term "photorefractive keratec-tomy", which consists in scraping off the corneal epithelium and applying the laser on the Bowman's membrane.

Full browser ?