What is a sclera: structure, function, disease

The human eye is a unique organ that can perform many functions. It has a peculiar structure. However, not everyone knows what a sclera is and what diseases of this part of the eye exist. To begin with it is necessary to understand the structure of the eye.

What is the

sclera? The eye sclera is the outer shell of the eyeball, which has a large area and covers 5/6 of the entire surface of the optic organ. In fact, it is a dense and opaque fibrous tissue. The thickness and density of the sclera in some places is not the same. The range of changes in the first index of the outer shell can be 0.3-1 millimeter.

External layer of sclera

So what is a sclera? This is a kind of fibrous tissue, which consists of several layers. In this case, each of them has its own peculiarities. The outer layer is called episcleral. There is a large number of blood vessels that provide a qualitative blood supply to tissues. In addition, the outer layer is reliably connected to the outer part of the eye capsule. This is its main feature.

Since the main part of the blood vessels passes through the muscles to the anterior part of the visual organ, the upper part of the outer layer differs from the internal parts by intensive blood supply.

Deeper layers of

The sclera itself consists mainly of fibrocytes and collagen. These components are very important for the body as a whole. The first group of substances takes an active part in the production of collagen itself, as well as in the separation of its fibers. The inner, the last layer of the fabric is called the "brown plate".It contains a large amount of pigment, which causes a specific shade of the shell of the eye.

For the coloration of such a plate, certain cells - chromatophores - are responsible. They are contained in the inner layer in large quantities. The brown plate most often consists of a thin scleral fiber, as well as a minor admixture of the elastic component. Outside this layer is covered with endothelium.

All blood vessels, as well as nerve endings located in the sclera, pass through emissaries - special channels.

What functions are performed by

Sclera functions are very diverse. The first of them is due to the fact that the collagen fibers inside the tissue are not arranged in a strict order. Because of this, the rays of light are simply unable to penetrate the sclera. This tissue protects the retina from intense exposure to light and sunlight. Thanks to this function, a person is able to see well. This is the main purpose of the sclera.

This fabric is designed to protect the eyes not only from intense lighting, but also from all sorts of damages, including those of a physical and chronic nature. In addition, the sclera protects the eyes from the effects of harmful environmental factors.

Also worth highlight is another function of this fabric. Conditionally it can be called a wireframe. It is the sclera that is a qualitative support and at the same time a reliable element of fixing the ligaments, muscles and other components of the eye.

Congenital diseases

Despite a fairly simple structure, there are certain diseases and pathologies of the sclera. Do not forget that this tissue performs important functions and if any disturbances occur, the visual apparatus as a whole deteriorates sharply. Diseases can reduce visual acuity and lead to irreparable consequences. Sclera ailments can be not only congenital, but also caused by various irritants and have acquired character.

This pathology, like blue sclera, often occurs as a result of the genetic predisposition and incorrect formation of the tissues that connect the eyeball, even in the womb. An unusual shade is explained by the small thickness of the layers. Through the thin sclera the pigment of the shell of the eyes is shining. It should be noted that this pathology often occurs with other anomalies of the eyes, as well as violations of the processes of formation of the organs of hearing, bone tissue and joints.

Scleral diseases are most often congenital. Melanosis also applies to such. When this ailment develops, dark spots form on the surface of the sclera. Patients with a similar diagnosis should be registered with an ophthalmologist. With the development of such a disease requires regular observation, as well as timely prevention of the development of serious complications.

Acquired ailments

Scleral inflammation is quite common. Diseases that arise as a result of this process deserve special attention. The development of such ailments can provoke not only general disturbances in the functioning of certain systems of the human body, but also infections. Often pathogenic organisms penetrate into the tissues of the outer eye shell with a stream of lymph or blood. This is the main cause of the inflammatory process.

In conclusion

Now you know what a sclera is and what diseases of this tissue exist. Treatment of her ailments begins with the diagnosis and consultation of a doctor. Only a specialist can prescribe therapy for the disease by determining all the symptoms. When developing ailments of the sclera it is recommended to consult an ophthalmologist. The specialist must conduct a number of laboratory studies. After the diagnosis is prescribed therapy.

If the disease is caused by a violation in other body systems, the treatment will be directed at eliminating the underlying cause. Only after this will be carried out activities to restore vision.