Corneal epithelium
The corneal epithelium 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. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...

. It acts as a barrier to protect the cornea, resisting the free flow of fluids from the tears, and prevents bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 from entering the epithelium and corneal stroma.

The corneal epithelium consists of several layers of cells. The cells of the deepest layer are columnar
Simple columnar epithelium
A simple columnar epithelium is a columnar epithelium that is uni-layered. In humans, a simple columnar epithelium lines most organs of the digestive tract including the stomach, small intestine, and large intestine...

, known as basal cells. Then follow two or three layers of polyhedral cells, commonly known as wing cells. The majority of these are prickle cell
Prickle cell
A prickle cell is an epidermal cell which lies above the basal cell layer, constituting a stratum spinosum, which forms innumerable intercellular bridges. These intercellular bridges give the stratum spinosum a rough appearance to which the cells of which it is composed owe their name...

s, similar to those found in the stratum mucosum of the cuticle. Lastly, there are three or four layers of squamous cells, with flattened nuclei
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...

. 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.

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. Epithelial ingrowth is a rarely occurring LASIK
LASIK or Lasik , commonly referred to simply as laser eye surgery, is a type of refractive surgery for correcting myopia, hyperopia, and astigmatism...

 complication, appearing in less than one percent of LASIK procedures. However, the incidence of epithelial ingrowth appears to be higher after subsequent enhancement LASIK procedures. This complication is not present in PRK
PRK could refer to:*Phase Reversal Keying, see BPSK*Photorefractive keratectomy, a laser eye surgery procedure*ISO 3166-1 alpha-3 code, International Olympic Committee country code, and FIFA country code for North Korea...

or other non-flap vision correction procedures.

External links

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