corneal epithelium

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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


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 ?
Oral and corneal epithelium also plays a critical role as a microbial barrier (10).
While any breakdown of the corneal epithelium could provide a possible route for microorganisms to enter the eye, more-severe cases of staining could lead to ulceration or scarring," Nichols points out.
The transplanted membrane gradually became transparent and in two-thirds of the cases dissolved within 3 months, replaced by corneal epithelium.
In a more experimental procedure - laser assisted in situ keratomileusis (LASIK) - the corneal epithelium is not removed, thereby reducing wound healing complications.
When cross-linking is used to treat degenerative keratoconus or post-LASIK ectasia, the corneal epithelium is commonly removed to allow riboflavin to penetrate into the cornea.
11) Data show that the corneal epithelium and Bowman's membrane can act as barriers to the penetration of UVA light into the stroma so by performing the two procedures simultaneously with the ablation first, the efficacy of CXL increases.
Positive results with RGN-259 have also been seen in patients with chronic neurotrophic keratopathy, a degenerative disease of the corneal epithelium resulting from impaired corneal innervation that may cause ulceration and perforation of the cornea.
during a study found that the applying other growth factors derived from platelets on the corneal epithelium, increase their development and trophism, these findings are consistent with our results that showed rapid wound healing and fast return of corneal transparency [11,16,17].
Auto- and allograft limbal transplantations are effective in restoring the corneal epithelium and inhibiting inflammation and neovascularization.
By one month, the ocular surface was covered with corneal epithelium, and the clarity of the cornea was improved.
In the first presentation, "Developing a Bandage Contact Lens Delivery System for Controlled Release of Thymosin Beta 4 to the Corneal Epithelium," Dr.
Other models of the tear film have been proposed and it is now recognised that there are dissolved mucins throughout the aqueous layer, decreasing in concentration from the surface of the corneal epithelium to the lipid layer.

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