corneal stroma

corneal stroma 

The thickest layer of the cornea located behind Bowman's layer and in front of Descemet's membrane. It represents approximately 90% of the total corneal thickness and gives the cornea its strength. The stroma consists of about 300 lamellae of parallel collagen fibrils in the centre of the cornea reaching to nearly 500 lamellae at the limbus. In between the fibrils are proteoglycans whose core proteins bind one with keratan sulfate and the other with dermatan sulfate (chondroitin sulfate B). The orientation of the alternate lamellae differs with each other, but they are all parallel with the corneal surface. In the central part of the cornea the majority of the collagen fibrils are orientated in the inferior-superior and nasal-temporal directions, whereas at the limbus they are orientated circumferentially, providing greater resistance to forces perpendicular to the axes of the fibrils. Between the lamellae are found the elongated flattened keratocytes (corneal corpuscles) from which the collagen fibrils are produced during development. When the cornea becomes oedematous due to trauma, disease or hypoxia, some of the fibrils lose their usual uniform calibre, become displaced and fluid accumulates between the lamellae, the stroma then loses its transparency. Syn. substantia propria.
References in periodicals archive ?
In humans, the corneal stroma occupies 90% of the corneal thickness and plays an important role in maintaining corneal transparency and strength.
A central 7 mm round corneal deepithelialization for efficient penetration of riboflavin through exposed corneal stroma was performed with the help of sterile blunt spatula.
Spontaneous chronic corneal epithelial defects in people are associated with basement membrane dystrophy, whereas in dogs, stromal alterations likely have a crucial role in the disease, causing a failed union between the epithelial basement membrane and the anterior layers of the corneal stroma.
It results in thinning of the corneal stroma, corneal ectasia, irregular astigmatism, and reduced vision.
17 in a prospective, non-comparative, interventional study evaluated the results of integration of amniotic membrane into corneal stroma.
Corneal endothelium is the innermost layer of hexagonal non-replicating neural crest derived tissue that is responsible for maintaining corneal deturgence throughout life by pumping excess fluid out of the stroma and keeping the corneal stroma in its usual dehydrated state4.
Laser ablation of the corneal stroma beneath the flap alters the curvature and thickness of the stroma resulting in an alteration to the refractive power of the cornea.
A corneal ulcer when present results in a break in corneal epithelium that exposes underlining corneal stroma (Slatter and Hakason 1993).
They also used the cells to develop constructs of corneal stroma akin to natural tissue.
The new layer is located at the back of the cornea between the corneal stroma and Descemet's membrane.
The study shows that the new layer, is located at the back of the cornea between the corneal stroma and Descemet's membrane, makes an important contribution to the sieve-like trabecular meshwork in the cornea.