The corneal epithelium (epithelium corneæ anterior layer) is made up of epithelial tissue and covers the front of the
cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...
. It acts as a barrier to protect the cornea, resisting the free flow of fluids from the tears, and prevents
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
from entering the epithelium and corneal stroma.
Anatomy
The corneal epithelium consists of several layers of cells. The cells of the deepest layer are
columnar
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
, known as basal cells which are attached by multiprotein complexes known as
hemidesmosomes
Hemidesmosomes are very small stud-like structures found in keratinocytes of the epidermis of skin that attach to the extracellular matrix. They are similar in form to desmosomes when visualized by electron microscopy, however, desmosomes attach t ...
to an underlying basement membrane.
Then follow two or three layers of polyhedral cells, commonly known as wing cells. The majority of these are
prickle cells, similar to those found in the
stratum mucosum of the cuticle. Lastly, there are three or four layers of
squamous
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
cells, with flattened
nuclei. The layers of the epithelium are constantly undergoing
mitosis. Basal and wing cells migrate to the anterior of the cornea, while squamous cells age and slough off into the tear film.
Central thickness of corneal epithelial layer is approximately 50 to 52 μm.
Cornea cell LASIK complication
Epithelial ingrowth is a LASIK complication in which cells from the cornea surface layer (epithelial cells) begin to grow underneath the corneal flap. This complication is not present in
PRK or other non-flap vision correction procedures.
See also
*
Stratified squamous epithelium
Disorders
*
Peripheral ulcerative keratitis
Peripheral Ulcerative Keratitis (PUK) is a group of destructive inflammatory diseases involving the peripheral cornea in human eyes. The symptoms of PUK include pain, redness of the eyeball, photophobia, and decreased vision accompanied by distinc ...
*
Recurrent corneal erosion
Recurrent corneal erosion is a disorder of the eyes characterized by the failure of the cornea's outermost layer of epithelial cells to attach to the underlying basement membrane ( Bowman's layer). The condition is excruciatingly painful because ...
External links
Epithelium Ingrowth After LASIK
References
{{DEFAULTSORT:Corneal Epithelium
Human eye anatomy