MedBucket

Cornea is a part of the outer layer of the eye. Its main characteristic is its transparency. Cornea has two sides, the outer (anterior) and the inner (posterior) one, and a border. The outer side is convex and smooth, covered with conjunctiva. The inner side is concave — more than the outer side is convex, causing the cornea to be differently thick. The wider parts are thicker (1.1mm), while the central parts are thinner (0.8mm). Cornea’s border gets between the lips of sclera, thus creating a formation called limbus corneae.

The cornea is made out of five layers:

1. epithelium anterius cornae
2. lamina limitans anterior
3. substantia propria corneae
4. lamina limitans posterior
5. endothelium camerae anterioris

1. The first layer is a classic epithelium made out of five layers of cells. The bottom layer is consisted of cylindrical cells, which form and produce the upper layers.

2. This membrane is a very thin membrane which is located between the epithelium and the substantia propria. It’s homogeneous and it provides the next layer with a smooth basis.

3. Substantia propria corneae is made out of bundles of binder fibrils, which form lamelles. The fibrils located within one lamelle cross each other (90° angle) with fibrils in other lamelles. Between the fibrils and the lamelles there are various spaces filled with corneal cells and lymph.

4. This membrane is a very thin, but elastic membrane. It is very strong and easily resists pathological processes.

5. This layer is a typically simple endothelium with huge nucleuses. It prevents the eye water to pass in the substantia propria.

Cornea doesn’t have any blood vessels — they are located on a peripheral location. If there were blood vessels in cornea, the light couldn’t get through. The innervation is prolific. The nerves come from the ciliary nerves and form a plexus near the sinus venosus sclerae. Branches of that plexus go to the inner parts and form two other plexuses — plexus cornealis profundus and plexus subepithelialis. The latter’s branches form the plexus interepithelialis.