Sclera - outer shell eyeball, which covers 5/6 of its area. At the expense of high density tissue, the sclera acts as a kind of opaque capsule with variable thickness.
Scleral structure
There are three layers in the structure of the sclera:
- External, which is called episclera;
- Middle, or sclera proper;
- Internal (brown plate).
The episclere has a large number of blood vessels that supply oxygen to the blood. In the upper areas, blood flow is more powerful than in the rest of the parts. This pattern is associated with the fact that most of the vessels come from the muscle fibers in the anterior part of the eyeball.
The middle layer contains many collagen fibers and fibrocytes. The latter produce collagen as needed.
The brown plate contains a large amount of pigment, which gives a specific color to the tissues of this layer. The pigment cells that are found in the inner layer of the sclera are called zromatophores. The endothelium is located on top of the brown plate.
The entire thickness of the sclera is penetrated by nerve fibers and vascular bundles that pass through special channels (emissaries).
Physiological sclera
The main role of the sclera is protective, it warns Negative influence external factors(mechanical and physical) on the internal structures of the eye. This ensures the normal functioning of the eye and clear vision of objects. In addition, some muscle fibers are attached to the sclera, which help the eye move when exploring the outside world. This important function of the sclera is called support.
Video about the structure of the sclera of the eye
Scleral lesion symptoms
With a scleral disease, the following symptoms are characteristic:
- Scleral rupture;
- The formation of dark spots on the surface;
- Decreased general visual acuity;
- Changes in the structure of collagen fibers.
Diagnostic methods for scleral lesions
To identify pathology with suspected scleral disease, perform the following manipulations:
- External visual inspection;
- eyes;
- eyes using a microscope.
Once again, it should be recalled that the main function of the sclera is a protective one, due to which it protects the eye from mechanical influence and negative environmental factors. In this regard, it is very important to care for this structure of the eye properly and undergo examinations by doctors to identify pathology.
Diseases of the sclera
Due to the fact that the sclera protects the eye from external influences and provides a supporting function, disruption of its work negatively affects the entire optical system... Among the diseases of the sclera, the following groups are distinguished:
- Congenital (in particular, melanosis);
- Acquired (eg, staphyloma,).
With a decrease in thickness, the color of the sclera changes. Sometimes this is due to a disorder in the area of the hearing aid. With melanosis, dark spots on the surface of the sclera.
With inflammation in the area of the eyeball, the process can affect other body systems, and therefore requires intervention.
Is an inflammatory process that affects the entire thickness of the outer connective tissue membrane of the eyeball. Clinically manifested by hyperemia, vascular injection, edema, pain on palpation of the affected area or movement of the eyeball. Diagnosis of scleritis is reduced to an external examination, biomicroscopy, ophthalmoscopy, visometry, tonometry, fluorescence angiography, ultrasound examination(SPL) in B-mode, computed tomography... Depending on the form of the disease, the treatment regimen includes local or systemic use of glucocorticoids and antibacterial agents... With purulent scleritis, an abscess opening is shown.
General information
Scleritis is an inflammatory disease of the sclera characterized by a slowly progressive course. Among all forms, the most common is anterior scleritis (98%). The defeat of the posterior sclera is observed in only 2% of patients. Variants of the course of pathology without necrosis prevail over necrotizing ones, which is associated with a favorable prognosis. With rheumatoid and reactive chlamydial arthritis, diffuse variants of the disease are common. In 86% of cases of ankylosing spondylitis, scleritis nodosa is diagnosed. In 40-50% of patients pathological changes sclera are combined with joint lesions of inflammatory genesis, and in 5-10% of cases, arthritis is accompanied by scleritis. The disease is more common in females (73%). The peak incidence is between 34 and 56 years of age. In children, pathology is observed 2 times less often.
Scleritis reasons
The etiology of scleritis is directly related to a history of systemic diseases. Triggers of scleral lesions are rheumatoid arthritis, Wegener's granulomatosis, juvenile idiopathic, reactive chlamydial or psoriatic arthritis, polyarthritis nodosa, ankylosing spondylitis, and recurrent polychondritis. Less commonly, this pathology develops in postoperative period after surgical removal of the pterygium or traumatic injury. Described clinical cases infectious scleritis in patients with a history of vitreoretinal surgery.
To sclerit infectious etiology often leads to dissemination of the process from the area of ulceration on the cornea. Inflammation can also be a source of infection. paranasal sinuses nose. The most common causative agents of the disease are Pseudomonas aeruginosa, Varicella-Zoster virus and Staphylococcus aureus... In rare cases, scleritis is of fungal origin. Medical lesion of the sclera often develops when taking mitomycin C. Risk factors - a history of osteoarticular forms of tuberculosis, systemic inflammatory diseases.
Scleritis symptoms
From a clinical point of view in ophthalmology, anterior (non-necrotizing, necrotizing), posterior and purulent scleritis are distinguished. Non-necrotizing scleral lesions are diffuse or nodular. Necrotizing may or may not be accompanied by an inflammatory process. In some cases, the course of scleritis is characterized by short-term self-terminating episodes. In the same time, pathological process in the sclera provokes its necrosis with the involvement of the underlying structures. For this disease an acute onset is characteristic, sluggish variants are less often observed. With diffuse scleritis, the entire anterior part of the outer connective tissue membrane of the eyeball is involved in the inflammatory process. Nodular lesion is accompanied by a decrease in visual acuity.
For the anterior scleritis, a slowly progressive course is characteristic. This form is accompanied by binocular damage to the organ of vision. Patients note severe pain when touching the area of edema projection, photophobia. The long course of the disease leads to damage to the sclera around the circumference of the limbus (annular scleritis) and the occurrence of severe keratitis, iritis or iridocyclitis. With purulent scleritis, rupture of the abscess membranes is possible, which leads to the development of iritis or hypopyon.
With a necrotic lesion of the sclera, patients notice increasing pain, which later becomes constant, radiating to the temporal region, the superciliary arch and the jaw. Pain syndrome is not stopped by taking analgesics. Necrotizing scleritis is complicated by scleral perforation, endophthalmitis or panophthalmitis. With the posterior form of pathology, patients complain of pain when moving the eyeball, limiting its mobility. Postoperative scleritis develops within 6 months after surgical intervention... In this case, a site of local inflammation is formed, which is replaced by necrosis. A decrease in visual acuity is observed only when the inflammatory process spreads to the adjacent structures of the eyeball or the development of secondary glaucoma.
Diagnosis of scleritis
Diagnostics of scleritis includes external examination, biomicroscopy, ophthalmoscopy, visometry, tonometry, fluorescence angiography, ultrasound examination (UZD) in B-mode, computed tomography. External examination of patients with anterior scleritis reveals swelling, hyperemia and vascular injection. The area of edema has delineated boundaries. Soreness is noted on palpation. Biomicroscopy in "gelatinous" scleritis allows you to identify the area of overhang of the chemosis conjunctiva over the limbus. This area has a reddish brown tint and a gelatinous consistency. Infiltrates with pronounced vascularization can be found on the surface of the cornea. By the method of biomicroscopy with a slit lamp with diffuse scleritis, a violation of the physiological radial direction of the vascular pattern is determined. In nodular form, visiometry indicates a decrease in visual acuity.
With purulent scleritis, an external examination reveals purulent infiltration and vascular injection. The defeat of the posterior sclera is accompanied by edema of the eyelids, conjunctiva and minor exophthalmos. Ophthalmoscopy is used to determine the prominence of the disc optic nerve, subretinal lipid exudation, detachment of the retina and choroid caused by accumulation of exudate. Ultrasound in B-mode indicates a thickening of the posterior part of the outer connective tissue membrane of the eyeball, accumulation of exudate in the tenon space. Changes in scleral thickness can also be confirmed with CT.
With necrotizing scleritis, fluorescent angiography is used to determine the tortuous course, areas of vascular occlusion, and avascular zones. Slit lamp biomicroscopy allows you to visualize necrotic changes in the sclera, ulceration of the adjacent conjunctiva. Expansion of the necrosis zone is revealed in dynamics. The method of tonometry in patients with scleritis often reveals an increase in intraocular pressure (more than 20 mm Hg).
Scleritis treatment
The treatment regimen for scleritis includes the topical use of glucocorticoid and antibacterial drops for instillation. If the disease is accompanied by increased intraocular pressure, then the complex of therapy must be supplemented with topical antihypertensive drugs... The course of treatment includes taking non-steroidal anti-inflammatory drugs. In case of their intolerance, it is recommended to prescribe medications from the group of glucocorticosteroids. With scleritis without necrotic lesion, glucocorticoids and antibacterial drugs must be administered as subconjunctival injections. An alternative this method introduction is the reception of prolonged forms of glucocorticoids.
With the development of scleral necrosis, combined therapy with glucocorticosteroids and immunosuppressants is indicated. In cases of occurrence allergic reaction parallel to data medicines antiallergic and desensitizing drugs are used. At purulent form scleritis treatment tactics is reduced to carrying out massive antibacterial therapy... In this case, the oral and subconjunctival routes of administration of drugs from the group of fluoroquinolones, aminoglycosides and semisynthetic penicillins are used. An additional route of administration is electrophoresis. In the absence of the effect of drug therapy, surgical opening of the abscess is indicated. Also, the treatment regimen should include drugs for the treatment of the underlying pathology, against which scleritis developed. If the etiological factor is mycobacterium tuberculosis, anti-tuberculosis drugs for topical application are considered as auxiliary.
Forecast and prevention of scleritis
Specific prophylaxis of scleritis has not been developed. Nonspecific preventive measures boil down to timely treatment the main pathology, prevention of inflammation of the paranasal sinuses (sinusitis), adherence to the rules of asepsis and antisepsis during surgical interventions. Patients with a history of systemic diseases need to be examined by an ophthalmologist 2 times a year. The prognosis for life and working capacity depends on the timeliness of the diagnosis, the adequacy of treatment, the type of pathogen in case of an infectious lesion and the form of the disease. The most favorable option is diffuse forms of the disease. Pseudomonas aeruginosa scleritis often has a poor prognosis.
The opaque part of the fibrous membrane is the sclera of the eye. It covers 85% of all surfaces and is primarily responsible for the transmission of visual information to the brain. Features of its structure provide wide range functions. With anomalies and the development of pathologies, there is a risk of loss of vision. Scleral problems cause a number of characteristic symptoms, if present, you should see a doctor. Treatment depends on the current disease and the stage of its development, in most cases it is used drug treatment local character.
Scleral anatomy
The sclera is the white membrane of the eye, it is located outside and together with the cornea is fibrous tissue... Reaching the iris, it forms a dense protective ring. According to its physical characteristics, it has White color and an opaque structure, due to which a person has vision. This is a rather dense tissue of several layers, normally the thickness of the sclera reaches up to 1 mm. Despite this structure, the albuminous membrane of the eyeball can stretch, but this property decreases with age.
Shell structure
Density is ensured by the features of the anatomy. The structure of the sclera is a very complex process. The main component is collagen, it is located in a chaotic manner, thus causing the opacity of the eye. Full functionality is possible due to the multi-layered shell, while the scleral layers differ in composition and density:
The shell has a very complex and intricate structure.
- Outer layer. The thinnest ball, filled with a large number of blood vessels.
- Middle layer. It is also called scleral, it includes maximum amount collagen.
- The inner layer. Represents connective tissue in combination with the pigment part.
The visible part of the sclera is only the upper layer, the subsequent ones are located inside, but with depletion, protrusion is possible. This process is observed in ophthalmic pathologies.
What functions does it perform?
The multifunctionality of the shell is ensured by its complex structure. Each of the 3 layers plays a role and only a holistic effect guarantees full vision. All functions of the white membrane of the eye are quite diverse. First of all, we are talking about protecting the pupil from external damage. The sun negatively affects the condition of the eye. It is due to the refraction of light in the envelope that the pupil does not blind and the image appears. In addition, the sclera perform the following functions:
The sclera make it possible to move the eyes in the direction we need. - Ututaetsya attachment for the vascular and muscular apparatus.
- Provides blood outflow through venous branches.
- Responsible for the mobility of the eye.
- Conducts moisture through the venous sinus of the sclera.
- Provides safe nerve passes to the eyeball.
What does a healthy sclera look like?
You can distinguish the diseased state of the protein sphere from the healthy one by color. In infancy, the sclera is thin, so the membranes appear blue. This condition is not considered pathological and eventually goes away on its own. What color of proteins in an adult can indicate the genetic nature of the problem, dystrophic changes were formed at the intrauterine level.
Possible pathologies are indicated by the yellowness of the sclera. In this case, the shell looks dull and cloudy. Such changes may indicate the impact of the infection. Lesions are not only local in nature, kidney disease affects the color of proteins. In old age, fat cells can be in large quantities in the eyes, they can change color to yellow.
Diseases
The body is susceptible inflammatory processes that provoke bacteria. Pathologies that develop in the eyes at the level of the sclera are most often inflammatory in nature, provoked by infections. Moreover, the primary sources are not always located directly in the organ. Painful manifestations in the membrane of the eye can only act as symptoms of the main processes. First of all, the ophthalmologist looks for the main diseases of the sclera, these include the following:
- Scleritus. Pathology of an inflammatory nature, in which the inner layers of the shell are affected.
- Staphiloma. The disease is caused by destructive processes, as a result of which the shell is depleted.
- Episcleritis. The defeat of the upper layer, accompanied by the formation of nodules.
Developmental anomalies
Congenital pathological forms, they are difficult to diagnose and not always amenable to conservative treatment. These include blue sclera syndrome. This color may indicate an insufficient amount of iron in the blood. Often such an ailment is a non-one developmental deviation, other pathologies of the eyes, ears, and the musculoskeletal system are also observed.
With an excess amount of melanin, the layers acquire yellow. One more congenital pathology is melanosis or melanopathy. This ailment is also associated with pigmentation, only the shell turns yellow due to saturation with melanin. This process occurs as a result of a violation of carbohydrate metabolism. Changes in color can manifest themselves in different ways, with distinctive layers or spots appearing on the top layer.
The sclera of the eye is the most extensive membrane of the optic organ. It takes up to 5/6 of the entire area. The thickness of the sclera varies in different places and in some places reaches 1 mm. The sclera is completely opaque, it has a dull white color. In young children, the thickness of this shell is small, so visual pigment is visible through it, due to which the eye acquires a bluish tint. As the child grows up, the thickness of this shell increases.
The structure of the sclera and its functions
The sclera is the opaque membrane of the visual organs. Due to the density and opacity of the sclera, good vision and normal intraocular pressure. This shell serves to protect the visual organ from damage of a different nature.
This shell has several layers. The outer layer is literally penetrated by the vascular mesh, due to which a good blood supply is ensured. This area is associated with the outer area of the eyeball. The capillaries pass through the muscle layer to the anterior part of the optic organ. The outer layer has more intense blood circulation than the inner parts.
The sclera is composed of collagen and fibrocytes. This site is involved in the production of collagen and breaks it down into individual fibers.
The last layer is called brown. This layer acquired its name for the content of a special pigment, which gives color to this area. This pigmentation is caused by special cells called chromatophores.
The entire thickness of the sclera is penetrated with the smallest blood vessels and nerve endings. It is a very sensitive shell.
Diseases
There are several diseases of the sclera of the eye that can lead to permanent visual impairment. This is due to the fact that this section of the visual organ performs several important functions, and any violation persistently affects visual acuity. Diseases can be congenital and acquired and have different character... The most common acquired pathologies are:
If a person has sclera blue, then this may be caused by improper formation of the connective tissues of the eyes while still in the womb. Such an attractive color is due to the transparency of the layer and the fact that another pigment layer is visible through it. The cause of this pathology can be diseases of the joints and auditory organs.
Another ailment of the sclera of the eye is melanosis. In this case, characteristic specks are formed on the surface of the shell dark color... People with such a deviation should be registered with an ophthalmologist - this is necessary in order to avoid various complications in the form of retinal detachment and visual impairment.
Inflammatory diseases of this membrane of the optic organ are also quite common. It can lead to such ailments as a disruption of work. different bodies and systems and infections. Any infectious diseases, regardless of their location, can be the impetus for the development of eye diseases. This is due to the fact that pathogens with blood flow quickly spread throughout the body.
The doctor can correctly diagnose in one case or another after a preliminary examination.
Diagnostic methods
Before starting treatment, it is necessary to correctly diagnose the disease. For this, anamnesis is taken and the patient is examined. If necessary, examine the membranes of the visual organs under a microscope. In some cases, an eye ultrasound is required.
To correctly assess the patient's health, a detailed blood test is done. In some cases, it is necessary to consult a geneticist.
Symptoms for diseases of the sclera
Diseases proceed with characteristic symptoms for which it is easy to diagnose. Most often observed:
With melanosis of the eyes, dark spots form around the visual organs, most often they are smooth, but at times they rise slightly above the surface. They can spread to the skin around the eyebrows and to the forehead.
Congenital pathologies
Congenital diseases are spoken of when the color of the sclera or its shape changes. Such diseases are genetic and are rarely diagnosed. The pronounced blue color of the shell indicates such a pathology. Such patients have poor hearing and suffer from frequent bone fractures.
In this case, the color change is observed already at the birth of the child. In newborns with such an anomaly, the blueness of the eye is more pronounced than in healthy children, and does not go away by six months. The size of the eyes is usually not changed, but in addition there may be other visual impairments - color blindness, cataracts, corneal opacity. 
In severe cases, children with such a pathology die even in the prenatal period. But it also happens that a child suffers from frequent bone fractures and only by the adolescent period such cases become less.
Scleral cysts can also be congenital and acquired. The latter occur after eye injuries and penetrating wounds. Cysts meet different sizes and shapes. They are motionless and grow rather slowly. In this case, the treatment is surgical, the cyst is removed in the classical way or with a laser. With a strong thinning of the posterior wall of the cyst, it is necessary to carry out scleroplasty.
There are also tumors that affect this membrane. Such pathologies occur quite often and can be a complication of other oncological diseases... Problems with the sclera of the eye are often observed in patients with tuberculosis and diabetes mellitus.
Treatment in this case is mainly symptomatic, aimed at maintaining a normal state of health.
Treatment
Any treatment should begin with a high-quality diagnosis. Initially, the cause that led to the changes in the membranes of the eye is precisely determined. In some cases, it is enough to simply eliminate the root cause in order to normalize the patient's condition. In the treatment, medications, physiotherapy procedures and surgical methods are used.
The patient is prescribed drugs to reduce intraocular pressure, as well as anti-inflammatory drops and ointments. Treatment is always comprehensive.
If there is a severe deterioration in vision or a retinal rupture, then resort to surgical treatment... Strengthening of the posterior pole of the eye is often used. In patients with staphylomas, the sclera is shortened and alloplasty is performed. If the cause of the disorder is glaucoma, then the disease is initially treated with surgery.
After treatment, the patient is registered with an ophthalmologist for some time. This allows you to timely identify various deviations and avoid complications.
Prevention of scleral diseases
The visual organs are very sensitive to any negative factors. In order to maintain good vision for many years, it is necessary to adhere to the following recommendations of doctors:
- Eat wisely. The daily menu should be rich in plant foods rich in vitamins and minerals.
- Avoid injury to the visual organs.
- Pregnant women should not self-medicate and take any medications without a doctor's prescription.
- At the first signs of an illness of the visual organs, an ophthalmologist should be shown.
- If the ophthalmologist has prescribed treatment, it should be carried out according to the recommended course.
It is impossible to prevent genetic diseases of the eyes, but before planning a pregnancy, it is advisable for parents who have vision problems to visit genetics. If the newborn has congenital diseases eye, consultation of leading experts is necessary.
Diseases of the sclera are not such a common occurrence, but they always lead to visual impairment. Treatment of such diseases requires a balanced approach. If conservative methods they do not give a result for a long time, they resort to surgery.
