Cornea Research Paper

1693 Words 7 Pages
1.1 anatomy of the cornea
1.1.1 Anatomy of the Cornea
The cornea is important visual part of the eye, it’s a thin dome-shaped oval from the front and circular from behind and covers the front part of the eye which include iris, pupil and anterior chamber. It forms anterior 1\6 of the outer coat of the globe.[1] The sclera and the conjunctiva overlap the cornea more vertically than horizontally. Together with the lens, the cornea refract light, and it is approximately 43 diopters of the total refractive power[2]. The curvature of the lens, on the other hand, can be adjusted to tune the focus depending upon the object’s distance.[2] The cornea has unmyelinated nerve endings sensitive to touch, temperature and chemicals; a touch of the cornea
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Also, it gets the oxygen directly from the air by dissolves the oxygen in the tear and then diffuses throughout the cornea to keep it healthy. The most abundant soluble protein in mammalian cornea is albumin. In humans, the cornea has a diameter of about 11.5 mm (12mm in horizontal meridian and 11 mm in the vertical meridian) and a thickness of 0.5–0.6 mm in the center and 0.6–0.8 mm at the periphery. Its size at birth is equal 80% of the adult size and it’s reach adult size by age of 3 years. It borders the sclera by the corneal limbus.[3, 4]
Histologically the cornea has 5 layer from external service to internal the layers are epithelial, bowmen’s membrane, stroma, Descemet’s membrane and endothelial. Frist layer covers the front of the cornea is non-keratinized Stratified squamous epithelium layer which made up of thin epithelial multicellular tissue of fast growing and easily regenerated cells by multiplication in the basal layer with life span of roughly a week.[4]
I. Eepithelium
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It’s smooth, tough, acellular layer protect stroma and composed of strong randomly oriented fine collagen fibrils, mainly type I. Unlike the first layer, once the Bowman’s membrane is damaged, it cannot be regenerate [3] . thickness of the bowman’s layer in adult is 8-12 μm and become thinner with aging [4] . The function of the Bowman's membrane remains unclear and appears to have no critical function in corneal physiology[5] . However, it may act as strong resistance barrier against infection and injury and prevents direct traumatic contact with the corneal stroma and hence it is highly involved in stromal wound healing and the associated restoration of anterior corneal transparency at the morphological level [4-5]. It is well-demarcated from the corneal epithelium. So, it is easy to strip the epithelium from the Bowman’s

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