Stroma of cornea

Stroma of cornea is the thickest layer of the cornea, making up about 90% of the cornea's thickness. It is located between the Bowman's layer and the Descemet's membrane. The stroma is composed primarily of water and collagen fibers, which give the cornea its strength and elasticity.

Structure

The stroma of the cornea is composed of approximately 200 thin layers of collagen fibers. These fibers are arranged in a regular, parallel pattern that is essential for the cornea's transparency. The collagen fibers are produced by cells called keratocytes, which are found between the layers of collagen.

In addition to collagen, the stroma also contains a small amount of proteoglycans, which are proteins that are heavily glycosylated. The proteoglycans fill the spaces between the collagen fibers and help to maintain the regular arrangement of the fibers.

Function

The primary function of the stroma is to provide strength and elasticity to the cornea. The regular arrangement of the collagen fibers allows light to pass through the cornea without scattering, which is essential for clear vision.

The stroma also plays a role in the cornea's ability to heal after injury. The keratocytes in the stroma can transform into a type of cell called a fibroblast, which can produce new collagen fibers to repair damage to the cornea.

Clinical significance

Abnormalities in the stroma can lead to a variety of corneal diseases. For example, in keratoconus, the collagen fibers in the stroma become irregularly arranged, leading to a thinning and bulging of the cornea. In corneal dystrophy, deposits of material can accumulate in the stroma, interfering with its transparency.

Treatment for stromal disorders can include corneal transplantation, in which the diseased cornea is replaced with a healthy donor cornea, or corneal cross-linking, a procedure that strengthens the collagen fibers in the stroma to prevent further thinning and bulging.

See also

• Cornea
• Keratoconus
• Corneal dystrophy