The choroid of the eyeball. Choroid proper, choroidea

And. It consists of a huge number of intertwining vessels that form the Zinna-Galera ring in the area of \u200b\u200bthe optic nerve head.

Vessels of a larger diameter pass in the outer surface, and small capillaries are located inside. The main role that it plays includes nutrition of the retinal tissue (its four layers, especially the receptor layer c and). In addition to the trophic function, the choroid is involved in the removal of metabolic products from the tissues of the eyeball.

All these processes are regulated by Bruch's membrane, which is of small thickness and is located in the area between the retina and the choroid. Due to semi-permeability, these membranes can provide the unidirectional movement of various chemical compounds.

Choroid structure

There are four main layers in the structure of the choroid, which include:

The supravascular membrane located outside. It is adjacent to the sclera and consists of a large number of connective tissue cells and fibers, between which pigment cells are located.
The choroid itself, in which relatively large arteries and veins pass. These vessels are separated by connective tissue and pigment cells.
Choriocapillary membrane, which includes small capillaries, the wall of which is permeable to nutrients, oxygen, as well as decomposition and metabolic products.
Bruch's membrane consists of connective tissuewho have close contact with each other.

Physiological role of the choroid

The choroid has not only a trophic function, but also a large number of others, presented below:

Participates in the delivery of nutrients to the cells of the retina, including the pigment epithelium, photoreceptors, the plexiform layer.
In it, the ciliary arteries pass, which follow to the anterior, separating the eyes and feed the corresponding structures.
Delivers chemical agents that are used in the synthesis and production of visual pigment, which is an integral part of the photoreceptor layer (rods and cones).
Helps remove waste products (metabolites) from the eyeball area.
Helps to optimize intraocular pressure.
Participates in local thermoregulation in the eye area due to the formation of thermal energy.
Regulates the flow of solar radiation and the amount of heat energy emanating from it.

Video about the structure of the choroid

Symptoms of damage to the choroid

Pretty long time choroidal pathologies may be asymptomatic. This is especially true for the defeat of the macular region. In this regard, it is very important to pay attention to even minimal deviations in order to visit an ophthalmologist in a timely manner.

Among characteristic symptoms with a disease of the choroid, you can notice:

Narrowing of visual fields;
Flickering and arising before the eyes;
Decreased visual acuity;
Blurred image;
Formation (dark spots);
Distortion of the shape of objects.

Diagnostic methods for damage to the choroid

To diagnose a specific pathology, it is necessary to conduct an examination in the amount of the following methods:

Ultrasound procedure;
using a photosensitizer, during which it is well possible to examine the structure of the choroid, identify altered vessels, etc.
the study includes a visual examination of the choroid and the optic nerve head.

Diseases of the choroid

Among the pathologies affecting the choroid, the following are more common:

Traumatic injury.
(posterior or anterior), which is associated with an inflammatory lesion. In the anterior form, the disease is called uveitis, and in the posterior form, chorioretinitis.
Hemangioma, which is a benign growth.
Dystrophic changes (chorioderma, Herat's atrophy).
choroid.
Choroidal coloboma, characterized by the absence of an area of \u200b\u200bthe choroid.
Choroidal nevus - benign tumorcoming from the pigment cells of the choroid.

It is worth recalling that the choroid is responsible for the trophism of retinal tissues, which is very important for maintaining clear vision and clear vision. In case of dysfunction of the choroid, not only the retina itself suffers, but also vision in general. In this regard, if even minimal signs of the disease appear, you should consult a doctor.

The choroid is the most significant element of the vascular tract of the organ of vision, which also includes and. The structural component is widespread from the ciliary body to the optic nerve head. The basis of the shell is a collection of blood vessels.

The anatomical structure under consideration does not include sensory nerve endings. For this reason, all pathologies associated with its defeat can quite often pass without severe symptoms.

What is the choroid?

Choroid (choroid) - the central zone of the eyeball, located in the interval between the retina and the sclera. The network of blood vessels, as the basis of the structural element, is distinguished by its development and orderliness: large vessels are located on the outside, capillaries border the retina.

Structure

The shell structure includes 5 layers. Below is a description of each of them:

Periarticular space

The part of the space between the shell itself and the surface layer inside. Endothelial plates loosely connect the membranes to each other.

Supravascular plate

It contains endothelial plates, elastic fiber, chromatophores - cells-carriers of dark pigment.

Vascular layer

Presented by a brown membrane. The layer size indicator is less than 0.4 mm (varies on the quality of blood supply). The plate contains a layer of large vessels and an interlayer with a prevalence of veins of average size.

Vascular capillary plate

Most significant element. It includes small veins and arteries that pass into many capillaries - a regular enrichment of the retina with oxygen is ensured.

Bruch Membrane

A narrow plate, combined from a pair of layers. The outer layer of the retina is in close contact with the membrane.

Functions

The choroid has a key trophic function. It consists in a regulatory effect on material metabolism and nutrition. Apart from these, structural element takes on a number of minor functions:

regulation of the flow of sunlight and heat energy transported by them;
participation in local thermoregulation within the organ of vision due to the production of thermal energy;
optimization of intraocular pressure;
withdrawal of metabolites from the area of \u200b\u200bthe eyeball;
delivery of chemical agents for the synthesis and production of pigmentation of the organ of vision;
the content of the ciliary arteries feeding the proximal organ of vision;
transportation of nutrients to the retina.

Symptoms

For a rather long period of time, pathological processes, during the development of which the choroid suffers, can proceed without obvious manifestations.

The structures of the eyeball need constant blood supply. The most vascular-dependent structure of the eye is the one that performs receptor functions.

Even a short-term occlusion of the vessels of the eye can lead to serious consequences. The so-called choroid of the eye is responsible for the blood supply.

Choroid - choroid of the eye

In the literature, the choroid of the eye is usually called the choroid itself. It is part of the uveal tract of the eye. The uveal tract consists of the following three parts:

- colored structure surrounding. The pigment components of this structure are responsible for the color of the human eyes. Inflammation of the iris is called iritis or anterior uveitis.
... This structure is located behind the iris. The ciliary body contains muscle fibers that regulate the focus of vision. Inflammation of this structure is called cyclitis or intermediate uveitis.
Choroid. This is the layer of the uveal tract that contains the blood vessels. The vasculature is located at the back of the eye, between the retina and the sclera. Inflammation of the choroid itself is called choroiditis or posterior uveitis.

The uveal tract is called the choroid, but only the choroid is the vasculature.

Features of the choroid

Choroidal melanoma of the eye

The choroid is formed by a large number of vessels necessary for feeding the photoreceptors and epithelial tissues of the eye.

Choroidal vessels are characterized by extremely fast blood flow, which is provided by the inner capillary layer.

The capillary layer of the choroid itself is located under Bruch's membrane, it is responsible for the metabolism in the photoreceptor cells. Large arteries are located in the outer layers of the posterior choroidal stroma.

The long posterior ciliary arteries are located in the suprachoroidal space. Another feature of the choroid itself is the presence of a unique lymphatic drainage.

This structure is able to reduce the thickness of the choroid several times with the help of smooth muscle fibers. The drainage function is controlled by the sympathetic and parasympathetic nerve fibers.

The choroid has several main functions:

The choroid vasculature is the main source of nutrition.
By changing the blood flow of the choroid, the temperature of the retina is regulated.
The choroid contains secretory cells that produce tissue growth factors.

Changing the thickness of the choroid allows the retina to move. This is necessary in order for the photoreceptors to fall into the plane of focus of the light rays.

Weakened blood supply to the retina can cause age-related macular degeneration.

Choroid pathologies

Pathology of the choroid of the eye

Choroid is subject to a large number pathological conditions... It can be inflammatory diseases, malignant neoplasms, hemorrhages and other disorders.

The particular danger of such diseases is that the pathology of the choroid itself also affects the retina.

Major diseases:

Hypertensive choroidopathy. Systemic hypertension associated with increased blood pressure, affects the work of the vasculature of the eye. Anatomical and histological features choroid make it especially susceptible to damaging action high pressure... This condition is also called non-diabetic vascular eye disease.
Detachment of the choroid itself. The choroid is located fairly freely relative to the adjacent layers of the eye. When the choroid is detached from the sclera, hemorrhage is formed. Such a pathology can be formed due to low intraocular pressure, blunt trauma, inflammatory disease and oncological process. With choroidal detachment, visual impairment occurs.
Rupture of the choroid. Pathology arises from dullness. The rupture of the choroid can be accompanied by a fairly pronounced bleeding. The disease may be asymptomatic, but some patients complain of decreased vision and a feeling of pulsation in the eye.
Dystrophy of the choroid. Almost all dystrophic lesions of the choroid are associated with genetic disorders. Patients may complain of axial, loss of visual fields and inability to see in fog. Most of these disorders do not respond to treatment.
Choroidopathy. This is a heterogeneous group of pathological conditions characterized by inflammation of the choroid itself. Some conditions may be associated with a systemic infection of the body.
Diabetic retinopathy. The disease is characterized by metabolic disorders of the vasculature of the eye.
Malignant neoplasms of the choroid. These are various tumors of the choroid. Melanoma is the most common type of this growth. The elderly are more susceptible to such diseases.

Most diseases of the choroid itself have a positive prognosis.

Diagnostics and treatment

Anatomy of the eye: schematic

The vast majority of diseases of the choroid itself are asymptomatic. Early diagnosis is possible in rare cases - usually the detection of certain pathologies is associated with a routine examination of the visual apparatus.

Basic diagnostic methods:

Retinoscopy is an examination method that allows you to examine in detail the state of the retina.
- a method for detecting diseases of the fundus of the eyeball. With this method, most of the vascular pathologies of the eye can be detected.
... This procedure allows visualization of the vasculature of the eye.
Computed and magnetic resonance imaging. Using these methods, you can get a detailed picture of the state of eye structures.
- method of vascular imaging using contrast agents.

Treatment methods are different for each condition. The main treatment regimens can be distinguished:

Steroid drugs and medicinesreducing blood pressure.
Operational interventions.
Cyclosporins are powerful immunosuppressants.
Pyridoxine (vitamin B6) for certain genetic disorders.

Timely treatment of vascular pathologies will prevent retinal damage.

Prevention methods

Eye surgery

The prevention of diseases of the choroid is largely associated with the prevention of vascular diseases. It is important to observe the following measures:

Control of blood cholesterol composition in order to avoid the development of atherosclerosis.
Controlling the functions of the pancreas to avoid the development of diabetes.
Regulation of blood sugar in diabetes.
Treatment of vascular hypertension.

Compliance with hygiene measures will prevent some infectious and inflammatory lesions of the choroid itself. It is also important to treat systemic infectious diseases, since they often become the source of choroid pathology.

Thus, the choroid of the eye is the vasculature of the visual apparatus. Choroidal diseases also affect the condition of the retina.

Video about the structure and functions of the choroid (choroid):

The main task of the choroid is to provide uninterrupted nutrition to the four outer layers of the retina, including the layer of photoreceptors, and to remove metabolic products into the bloodstream. The layer of capillaries from the retina is delimited by a thin Bruch's membrane, whose function is to regulate the exchange processes between the retina and the choroid. The periosteal space, due to its loose structure, serves as a conductor for the posterior long ciliary arteries, which are involved in the blood supply to the anterior part of the organ of vision.

Choroid structure

The choroid belongs to the most extensive part in the vascular tract of the eyeball, which also includes the ciliary body and the iris. It runs from the ciliary body, bounded by the dentate line, to the limits of the optic nerve head.

Choroidal blood flow is provided through the posterior short ciliary arteries. And the blood flows through the vorticoid veins. A limited number of veins (one for each quadrant, the eyeball and massive blood flow contribute to a slow blood flow, which increases the likelihood of the development of infectious inflammation processes due to the settling of pathogens. There are no sensitive nerve endings in the choroid, so its diseases are painless.

In special cells of the choroid, chromatophores, there is a rich supply of dark pigment. This pigment is very important for vision, because light rays passing through open areas of the iris or sclera can interfere with good vision due to diffuse illumination of the retina or lateral glare. In addition, the amount of pigment contained in the choroid determines the degree of coloration of the fundus.

For the most part, the choroid, in accordance with its name, consists of blood vessels, including several more layers: the perivascular space, as well as the supravascular and vascular layers, the vascular-capillary layer and the basal layer.

The perichoroidal perivascular space is a narrow slit that delimits the inner surface of the sclera from the vascular plate, which is pierced by delicate endothelial plates connecting the walls. However, the connection between the choroid and the sclera in this space is rather weak and the choroid easily exfoliates from the sclera, for example, when intraocular pressure jumps during surgical treatment glaucoma. To the anterior segment of the eye from the posterior, in the perichoroidal space there are two blood vessels accompanied by nerve trunks are the long posterior ciliary arteries.
The supravascular plate includes endothelial plates, elastic fibers and chromatophores - cells containing dark pigment. Their number in the choroidal layers in the direction of the inward decreases markedly, and disappears in the choriocapillary layer. The presence of chromatophores often leads to the development of choroidal nevi, and melanomas, the most aggressive of malignant neoplasms, often occur.
The vascular plate is a brown membrane, the thickness of which reaches 0.4 mm, and the size of its layer is associated with the conditions of blood filling. The vascular plate includes two layers: large vessels with arteries lying outside and vessels of medium caliber, with predominant veins.
The choriocapillary layer, called the vascular capillary plate, is considered the most significant layer of the choroid. It provides the functions of the underlying retina and is formed from small highways of arteries and veins, which then break up into many capillaries, which allows more oxygen to enter the retina. A particularly pronounced network of capillaries is present in the macular region. The very close connection between the choroid and the retina is the reason that the processes of inflammation, as a rule, affect almost simultaneously both the retina and the choroid.
Bruch's membrane is a thin, two-layer lamina, very tightly connected to the choriocapillary layer. She is involved in regulating the supply of oxygen to the retina and the removal of metabolic products into the blood. Bruch's membrane is also associated with the outer layer of the retina - the pigment epithelium. In the case of predisposition, with age, sometimes there are dysfunctions of a complex of structures, including the choriocapillary layer, Bruchia's membrane, and pigment epithelium. This leads to the development of age-related macular degeneration.

Video about the structure of the choroid

Diagnosis of choroid diseases

Methods for diagnosing pathologies of the choroid are:

Ophthalmoscopic examination.
Ultrasound diagnostics (ultrasound).
Fluorescence angiography, with an assessment of the state of blood vessels, detection of damage to Bruch's membrane and newly formed vessels.

Symptoms of choroid diseases

Decreased visual acuity.
Distorted vision.
Twilight vision impairment (hemeralopia).
Flies before the eyes.
Blurred vision.
Lightning before the eyes.

Diseases of the choroid

Coloboma of the choroid or complete absence a certain area of \u200b\u200bthe choroid.
Choroid dystrophy.
Choroiditis, chorioretinitis.
Detachment of the choroid that occurs during intraocular pressure surges during ophthalmic operations.
Ruptures in the choroid and hemorrhages - more often due to eye injuries.
Choroidal nevus.
Neoplasms (tumors) of the choroid.

The choroid or choroid is the middle layer of the eye that lies between the sclera and the retina. Most of the choroid is represented by a well-developed network of blood vessels. The blood vessels are located in the choroid in a certain order - there are larger vessels outside, and inside, on the border with the retina, there is a layer of capillaries.

The main function of the choroid is to provide nutrition to the four outer layers of the retina, which includes the rod and cone layer, and to remove metabolic products from the retina back into the bloodstream. The capillary layer is delimited from the retina by a thin Bruch membrane, whose function is to regulate metabolic processes between the retina and the choroid. In addition, the peri-vascular space, due to its loose structure, serves as a conductor for the posterior long ciliary arteries involved in the blood supply to the anterior segment of the eye.

Choroid structure

The choroid itself is the most extensive part of the vascular tract of the eyeball, which also includes the ciliary body and the iris. It extends from the ciliary body, the border of which is the dentate line, to the optic nerve head.
Choroid is provided with blood flow through the posterior short ciliary arteries. The outflow of blood occurs through the so-called vorticose veins. A small number of veins - only one for every quarter, or quadrant, of the eyeball and pronounced blood flow help slow blood flow and a high probability of developing inflammatory infectious processes due to the settling of pathogenic microbes. The choroid is devoid of sensitive nerve endings, for this reason all its diseases are painless.
Choroid is rich in dark pigment, which is found in special cells called chromatophores. The pigment is very important for vision, as light rays entering through open areas of the iris or sclera would interfere with good vision due to spilled retinal lighting or lateral flares. The amount of pigment contained in this layer also determines the color intensity of the fundus.
According to its name, for the most part, the choroid consists of blood vessels. Choroid includes several layers: perivascular space, supravascular, vascular, vascular-capillary and basal layers.

The perivascular or perichoroidal space is a narrow gap between the inner surface of the sclera and the vascular plate, which is penetrated by delicate endothelial plates. These plates connect the walls together. However, due to the weak connections between the sclera and choroid in this space, the choroid peels off the sclera quite easily, for example, in case of intraocular pressure drops during operations for glaucoma. In the perichoroidal space, from the posterior to the anterior segment of the eye, two blood vessels pass - the long posterior ciliary arteries, accompanied by nerve trunks.
The supravascular plate consists of endothelial laminae, elastic fibers and chromatophores - cells containing dark pigment. The number of chromatophores in the layers of the choroid decreases rapidly from the outside to the inside, and they are completely absent in the choriocapillary layer. The presence of chromatophores can lead to the appearance of choroidal nevi and even the most aggressive malignant tumors - melanoma.
The vascular plate has the form of a brown membrane, up to 0.4 mm thick, and the layer thickness depends on the degree of blood filling. The vascular plate consists of two layers: large vessels lying outside with a large number of arteries and vessels of medium caliber, in which veins predominate.
The vascular capillary plate, or choriocapillary layer, is the most important layer of the choroid, ensuring the functioning of the underlying retina. It is formed from small arteries and veins, which then disintegrate into many capillaries, allowing several red blood cells to pass in one row, which allows more oxygen to enter the retina. The network of capillaries is especially pronounced for the functioning of the macular region. The close connection of the choroid with the retina leads to the fact that inflammatory diseases, as a rule, affect both the retina and the choroid together.
Bruch's membrane is a thin plate made up of two layers. It is very tightly connected to the choriocapillary layer of the choroid and is involved in regulating the flow of oxygen to the retina and metabolic products back into the bloodstream. Bruch's membrane is also associated with the outer layer of the retina, the pigment epithelium. With age and in the presence of a predisposition, a dysfunction of a complex of structures may occur: the choriocapillary layer, Brucha's membrane and pigment epithelium, with the development of age-related macular degeneration.

Methods for diagnosing diseases of the choroid

Ophthalmoscopy.
Ultrasound diagnostics.
Fluorescence angiography - assessment of the state of blood vessels, damage to Bruch's membrane, the appearance of newly formed vessels.

Symptoms for diseases of the choroid

Congenital changes:

Coloboma of the choroid is the complete absence of the choroid in a certain area.

Purchased changes:

Choroid dystrophy.
Inflammation of the choroid - choroiditis, but more often combined with damage to the retina - chorioretinitis.
Detachment of the choroid, with changes in intraocular pressure during abdominal operations on the eyeball.
Rupture of the choroid, hemorrhage - most often due to eye injuries.
Choroidal nevus.
Tumors of the choroid.