The vascular tract of the eye consists of. Vascular tract, its three divisions, functions
39. Vascular tract, structure, physiology, features of vascularization and innervation. Classification of diseases of the vascular tract.
Middle layer of the eye is vascular tract of the eye, which embryogenetically corresponds to the pia mater and consists of three parts: the choroid itself (choroid), the ciliary body and the iris. The vascular tract is separated from the sclera by the suprachoroidal space and is adjacent to it, but not all the way. It consists of branching vessels of various calibers, forming a tissue resembling a cavernous tissue in structure.
Anterior part of the vascular tract is Iris. It is visible through a transparent cornea, painted in one color or another, which indicates the color of the eyes (gray, blue, brown). In the center of the iris is the pupil, which, thanks to the presence of two muscles (sphincter and dilator), can narrow to 2 mm and expand to 8 mm to regulate the entry of light rays into the eye.
The sphincter is innervated by the parasympathetic oculomotor nerve, the dilator is sympathetic, penetrating from the plexus caroticus.
ciliary body inaccessible to inspection with the naked eye, unlike the iris. Only with gonioscopy, at the top of the chamber angle, one can see a small area of the anterior surface of the ciliary body, slightly covered by the delicate fibers of the uveal part of the trabecular apparatus. The ciliary body is a closed ring, about 6 mm wide. On the meridian section, it has the shape of a triangle. In the ciliary body, on its inner surface, there are 70-80 processes. The ciliary body consists of smooth ciliary or accommodative muscle. From the inside, the ciliary body is lined with two layers of epithelium - a continuation of the embryonic retina. On the surface of the epithelium there is a boundary membrane to which the fibers of the zonium ligament are attached. The ciliary body performs a very important function, its processes produce intraocular fluid, which nourishes the avascular parts of the eye - the cornea, lens, vitreous body. The ciliary epithelium has a huge number of nerve endings. In newborns, the ciliary body is underdeveloped. In the first years of life, the motor and trophic nerves are better developed than the sensory ones; therefore, during inflammatory and traumatic processes, the ciliary body is painless. By the age of 7-10 years, the ciliary body is the same as in adults.
The choroid proper or choroid extends from the dentate line to the opening of the optic nerve. In these places it is tightly connected with the sclera, and in the rest of its length it is adjacent to the sclera, separated from it by the suprachoroidal space, where the ciliary vessels and nerves pass. Microscopically, several layers are distinguished in the choroid: the suprachoroid, the layer of large vessels, the layer of medium vessels, the choriocapillary layer with an unusual width of the capillary lumen and narrow intercapillary lumens.
The choriocapillary layer provides nutrition to the outer layers of the retina, i.e. neuroepithelium.
Diseases of the choroid include inflammatory diseases of an infectious or toxic-allergic nature ( iritis, iridocyclitis, endophthalmitis, panuveitis), dystrophic processes, tumors and injuries, as well as congenital anomalies
Anomalies of the choroid, which are occasionally found in newborns, include aniridia, coloboma of the iris, ciliary body and choroid proper, polycoria, corectopia, freckles, aplasia, albinism.Aniridiait is the absence of the iris. At the same time, behind the cornea there is a picture of a maximally dilated pupil, that is, blackness. Even with side illumination, the contours of the lens and the ciliary band are visible. Sometimes a rim is visible - the remnant (rudiment) of the iris root and ciliary processes. The most clear picture of aniridia is given by biomicroscopy and examination in transmitted light, while, according to the diameter of the cornea, a red reflex from the fundus is determined. Coloboma of the iris, ciliary body and choroid - the absence of part of the department.coloboma- the general name of some types of congenital, less commonly acquired defects in the tissues of the eye (the edge of the eyelid, the iris, the choroid itself, the retina, the optic disc, the lens). A congenital or acquired defect of the eye, leading to various anomalies: from the appearance of a small indentation of the edge of the eyelid or the lower part of the iris, as a result of which the pupil resembles a pear, to defects in the fundus. An enlarged pupil leads to the appearance of symptoms of blindness in a person. Eyelid coloboma is a congenital depression at the edge of the eyelid
Polycoria- these are two or more pupils; one of them is larger, and the rest are smaller; the shape of these pupils is not quite round, and the reaction to light is sluggish. Naturally, with this condition of the iris, there is a pronounced visual discomfort and a decrease in visual acuity.
Corectopia Characterized by an eccentric pupil. If there is a shift to the nasal, i.e., to the optical zone, then a sharp decrease in visual acuity is possible and, as a result, the development of amblyopia and strabismus.
Interpupillary membrane is the most harmless anomaly, which is often found in children. It can have a bizarre shape in the form of a web, oscillating in the aqueous humor of the anterior chamber, as a rule, fixed to the iris and the anterior lens capsule. Pronounced and dense membranes in the central zone of the lens can reduce visual acuity.
Inflammatory diseases of the vascular tract: iris - iritis, ciliary body - cyclitis, iridocyclitis or anterior uveitis, damage to the vascular tract - posterior uveitis or choreoiditis, iridocyclochoroiditis, panuveitis, generalized uveitis. The infection enters by exogenous or endogenous routes.
Irit- inflammation of the iris or iris and ciliary body (iridocyclitis).
Uveitis- inflammation of the choroid of the eyeball. Anatomically, the choroid of the eyeball is divided into the iris, the ciliary body and the choroid itself, located behind the ciliary body and making up almost 2/3 of the choroid (actually lines the retina from the outside).
Iridocyclitis- acute inflammation of the iris and ciliary body, or anterior uveitis.
Tumors of the vascular tract- from benign formations there are neurofibromas, neurinomas, leiomyomas, nevi, cysts. You can notice changes in the eye if they are localized in the anterior segment. They are manifested in one way or another in a change in the structure and color of the iris. The most obvious are nevi and cysts
Melanoma- malignant pigment tumor, can occur in the iris, ciliary body, choroid. Choroidal melanoma is the most common tumor of the uveal tract, characterized by rapid growth and metastasis.
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18-09-2011, 06:59
Description
Inflammatory diseases of the vascular tract account for 7 to 30% of all eye diseases. There are 0.3-0.5 cases of the disease per 1000 population. In 10% of cases of particularly severe uveitis, blindness develops in both eyes, and approximately 30% of patients develop visual impairment.
About 40% of cases of uveitis occur against the background of a systemic disease. With anterior uveitis associated with the presence of HLA-B27 Ag in the blood, men predominate (2.5:1).
The social significance of uveitis is also related to the fact that diseases of the vascular tract most often occur in young people of working age and can lead to a sharp decrease in visual acuity and blindness.
Changes in intrauterine eye pathology in children are especially severe. As a rule, they drastically reduce vision and make it impossible to study in general schools. Similar outcomes have been established in 75-80% of these children.
Features of the anatomy of the vascular tract
The structure of each of the three sections of the vascular tract - the iris, ciliary body and choroid has its own characteristics, which determines their function in normal and pathological conditions. Common to all departments are abundant vascularization and the presence of pigment (melanin).
The anterior and posterior sections of the choroid have separate blood supply. The blood supply to the iris and ciliary body (anterior section) is carried out from the posterior long and anterior ciliary arteries; choroid (posterior) - from the posterior short ciliary arteries. All this creates conditions for an isolated lesion of the vascular tract.
The selectivity of the lesion of the choroid is associated with the conditions of blood circulation (the anatomical structure of the uveal tract). Thus, blood enters the vascular tract through a few thin trunks of the anterior and posterior ciliary arteries, which break up into a vascular network with a much larger total lumen of the vessels. This leads to a sharp slowdown in blood flow. Rapid evacuation of blood is also prevented by intraocular pressure.
For these reasons, the vascular tract serves as a kind of "settlement pool" for infectious agents of their metabolic products. These can be live or dead bacteria, viruses, fungi, helminths, protozoa and their decay and metabolic products. They can also become allergens.
The third feature is different innervation. The iris and ciliary body are innervated from the first branch of the trigeminal nerve, and there is no sensory innervation in the choroid.
Classification of uveitis
Uveitis can be divided by etiology, localization, process activity and course. Be sure to evaluate the localization of the process.
Anterior uveitis includes iritis - inflammation of the iris and cyclitis - inflammation of the ciliary body, which mainly occur together as iridocyclitis.
Posterior uveitis includes inflammation of the choroid itself - choroiditis. Inflammation of all parts of the vascular tract is called panuveitis.
According to the etiology, uveitis is divided into endogenous and exogenous, according to the clinical course - into acute and chronic, according to the morphological picture - into granulomatous (metastatic hematogenous, focal) and non-granulomatous (toxic-allergic, diffuse).
Anterior uveitis is divided according to the nature of inflammation into serous, exudative, fibrinous-plastic and hemorrhagic. Posterior uveitis, or choroiditis, is classified according to the localization of the process into central, paracentral, equatorial and peripheral uveitis or parsplanitis. The process of uveitis is divided into limited and disseminated.
Pathogenesis of uveitis
When introducing infectious agents, exposure to other damaging factors, the reactions of specific cellular and humoral immunity are of great importance. The immune response to foreign substances is expressed in the rapid action of non-specific factors, interferon and inflammatory response.
In the immune organism, specific reactions of antigens with antibodies and sensitized lymphocytes play an active role. They are aimed at the localization and neutralization of the antigen, as well as its destruction with the involvement of the lymphoid cells of the eye in the process. The choroid, according to the definition of scientists dealing with these problems, is a target for immune reactions, a kind of lymph node in the eye, and recurrent uveitis can be considered a kind of lymphadenitis. A large concentration of mast cells in the choroid and the release of immune factors by them contribute to the entry into the depot and the exit of T-lymphocytes from this depot. The cause of recurrence may be an antigen circulating in the blood. Important factors in the development of chronic uveitis are a violation of the hematoophthalmic barrier that traps antigens. These are vascular endothelium, pigment epithelium, ciliary body epithelium.
In some cases, the resulting disease is associated with cross-reactive antigens of the vascular endothelium with antigens of the uveal tract, retina, optic nerve, lens capsule, conjunctiva, kidney glomeruli, synovial tissue and tendons of the joints. This explains the occurrence of syndromic lesions of the eye in diseases of the joints, kidneys, etc.
In addition, a number of microorganisms are neurotropic (toxoplasma and many viruses of the herpetic group). The inflammatory processes caused by them proceed in the form of retinitis, followed by damage to the choroid.
Clinic of iridocyclitis
The clinical picture of iridocyclitis is manifested primarily by a sharp pain in the eye and the corresponding half of the head, aggravated at night. The appearance of pain is associated with irritation of the ciliary nerves. Increased ciliary pain at night can be explained by an increase in the tone of the parasympathetic division of the autonomic nervous system at night and the exclusion of external stimuli, which fixes the patient's attention on pain sensations. The pain reaction is most pronounced in iridocyclitis of herpetic etiology and in secondary glaucoma. Pain in the region of the ciliary body sharply increases with palpation of the eye through the eyelids.
Irritation of the ciliary nerves in a reflex way causes the appearance of photophobia (blepharospasm and lacrimation). maybe visual impairment although vision may be normal early in the disease.
With developed iridocyclitis the color of the iris changes. So, the blue and gray irises acquire greenish hues, and the brown iris looks rusty due to the increased permeability of the dilated vessels of the iris and the ingress of red blood cells into the tissue, which are destroyed; hemoglobin at one of the stages of decay turns into hemosiderin, which has a greenish color. This, as well as infiltration of the iris, explains two other symptoms - shading of the picture irises and miosis- constriction of the pupil.
In addition, with iridocyclitis appears pericorneal injection, which often becomes mixed due to the active reaction of the entire system of the anterior ciliary arteries. In acute cases, petechial hemorrhages may occur.
The pain reaction to light intensifies at the moment of accommodation and convergence. To determine this symptom, the patient should look into the distance, and then quickly at the tip of his nose; this causes severe pain. In unclear cases, this factor, among other signs, contributes to the differential diagnosis with conjunctivitis.
Almost always with iridocyclitis are determined precipitates, settling on the posterior surface of the cornea in the lower half in the form of a triangle with the top up. They are lumps of exudate containing lymphocytes, plasma cells, macrophages. At the beginning of the process, the precipitates are grayish-white, then they become pigmented and lose their rounded shape.
The formation of precipitates is explained by the fact that blood elements, due to increased vascular permeability, enter the posterior chamber, and due to the very slow flow of fluid from it into the anterior chamber and from the pupil to the posterior surface of the cornea, blood cells have time to stick together with fibrin into conglomerates, which settle on the endothelium. cornea due to a violation of its integrity. Precipitates come in different sizes (point small and large fatty or sebaceous) and different saturation (light or dark gray, pigmented).
Precipitates on the corneal endothelium (Ehrlich-Turk line)
Frequent signs of iridocyclitis are clouding of the moisture of the anterior chamber - Tyndall's symptom of varying severity (depending on the number of cells in the field of view in the anterior chamber), as well as the appearance of hypopyon, which is a sterile pus. The formation of a hypopyon is caused by the penetration of blood cells (lymphocytes, macrophages, etc.), protein, and sometimes pigment into the anterior chamber. The type of exudate (serous, fibrinous, purulent, hemorrhagic) and its amount depend on the severity and etiology of the process. With hemorrhagic iridocyclitis, blood may appear in the anterior chamber - hyphema.
The next important symptom of iridocyclitis is the formation posterior synechia- adhesions of the iris and anterior lens capsule. The swollen, inactive iris is in close contact with the anterior surface of the lens capsule, so a small amount of exudate, especially fibrinous, is sufficient for fusion.
If the pupil is completely infected (circular synechia), the outflow of moisture from the posterior chamber to the anterior is blocked. The intraocular fluid, accumulating in the posterior chamber, protrudes the iris anteriorly. This state is called bombed iris. The depth of the anterior chamber becomes uneven (the chamber is deep in the center and shallow along the periphery), due to a violation of the outflow of intraocular fluid, the development of secondary glaucoma is possible.
When measuring intraocular pressure, normal or hypotension is noted (in the absence of secondary glaucoma). A reactive increase in intraocular pressure is possible.
The last constant symptom of iridocyclitis is the appearance exudate in the vitreous causing diffuse or flaky floaters.
Thus, the common signs of all iridocyclitis include the appearance of sharp ciliary pain in the eye, pericorneal injection, discoloration of the iris, blurring of its pattern, pupil constriction, hypopyon, formation of posterior synechia, precipitates, exudate in the vitreous body.
Differential Diagnosis
Acute iridocyclitis should be differentiated primarily from an acute attack of angle-closure glaucoma and acute conjunctivitis. The main parameters of differential diagnosis are given in Table. 2.
Table. Differential diagnosis of iridocyclitis
The angle of the anterior chamber is gradually obliterated, secondary glaucoma, complicated cataract, vitreal moorings of the vitreous body, traction retinal detachment develop.
For etiological diagnosis in the case of rheumatoid arthritis, it is important to detect common systemic disorders by careful questioning of the patient. Morning stiffness, hyperemia, inflammation of the joints are revealed.
Laboratory diagnostics includes the determination of rheumatoid factor, beta-lipoproteins, complement titer, the determination of urinary excretion of glycosaminoglycans and hydroxyproline as the main component found during the breakdown of collagen.
Tuberculous uveitis
Tuberculosis is a common cause of uveitis.
Diseases are accompanied by chronic proliferation without severe inflammation (tuberculomas form in the iris and ciliary body). Diseases have signs of an allergic reaction and are accompanied by active inflammation with severe exudation.
When determining the tuberculous genesis of uveitis, it is necessary to take into account:
Contact with a patient with tuberculosis;
Past tuberculosis disease of other organs (lungs, glands, skin, joints);
Data from X-ray, tomographic studies of the lungs and other organs;
Detection in the blood serum of patients with antibodies to tuberculin;
Strengthening of skin and intradermal tuberculin reactions during exacerbation of the eye process;
Focal reactions to intradermal injection and tuberculin electrophoresis, results of express diagnostics;
Decreased titers of lymphocyte sensitization antibodies during treatment.
Toxoplasmosis uveitis
There is focal chorioretinitis, usually bilateral; more often central, sometimes - near-disk localization. The disease recurs.
When taking the history, it is important to look for contact with animals, eating raw meat, or improper handling of raw meat.
In addition to the above causes of uveitis, it is necessary to note viral lesions of the vascular tract, syphilis, gonorrhea, leprosy, brucellosis, listeriosis, diabetes, AIDS, etc.
Treatment of uveitis
Treatment goals: suppression of an infectious etiological factor; blocking or regulation of local and systemic autoimmune reactions; replenishment of local (in the eye) and general deficiency of glucocorticosteroids.
To achieve these goals, conservative therapy is used with the obligatory use of glucocorticosteroids and extracorporeal methods (hemosorption, plasmapheresis, quantum autohemotherapy).
General principles of pharmacotherapy of uveitis:
Anti-inflammatory therapy;
The most effective drugs are glucocorticosteroids. For the treatment of anterior uveitis, corticosteroids are mainly used locally or in the form of subconjunctival injections; in the treatment of posterior uveitis, parabulbar injections are used. In severe processes, GCS is used systemically;
GCS is instilled into the conjunctival sac 4-6 times a day, an ointment is applied at night. The most commonly used 0.1% solution of dexamethasone [INN] (eye drops and Maxidex ointment);
0.3-0.5 ml of a solution containing 4 mg / ml of dexamethasone [INN] (Dexamethasone injection solution) is administered subconjunctival or parabulbarno. In addition, prolonged forms of corticosteroids are used: triamcinolone [INN] is administered 1 time in 7-14 days (injection solution of 10 mg / ml Kenalog), a complex of disodium phosphate and betamethasone dipropionate [INN] is administered 1 time in 15-30 days ( solution for injection diprospan);
In especially severe cases, systemic corticosteroid therapy is prescribed. In systemic therapy, the daily dose of the drug should be administered between 6 and 8 am before breakfast.
Distinguish between continuous corticosteroid therapy- oral prednisolone 1 mg / kg / day in the morning (average 40-60 mg), the dose is gradually reduced every 5-7 days by 2.5-5 mg (prednisolone tablets 1 and 5 mg) or prolonged forms intramuscularly GCS (kenalog) 80 mg (if necessary, the dose can be increased to 100-120 mg) 2 times with an interval of 5-10 days, then 40 mg is administered 2 times with an interval of 5-10 days, the maintenance dose is 40 mg with at intervals of 12-14 days for 2 months.
When conducting intermittent GCS therapy, a 48-hour dose is administered simultaneously, every other day (alternating therapy) or the drug is used for 3-4 days, then a break is made for 3-4 days (intermittent therapy). A variation of intermittent therapy is pulse therapy: intravenous methylprednisolone is administered at a dose of 250-500 mg 3 times a week every other day, then the dose is reduced to 125-250 mg, which is administered first 3 times a week, then 2 times a week;
With a moderately pronounced inflammatory process, NSAIDs are applied topically in the form of installations 3-4 times a day - a 0.1% solution of diclofenac sodium [INN] (Naklof eye drops). Topical application of NSAIDs is combined with their use orally or parenterally - indomethacin [INN] orally 50 mg 3 times a day after meals or rectally 50-100 mg 2 times a day. At the beginning of therapy, for faster relief of the inflammatory process, 60 mg intramuscularly is used 1-2 times a day for 7-10 days, then they switch to the use of the drug orally or rectally;
With the ineffectiveness of anti-inflammatory therapy in a pronounced process, immunosuppressive therapy is carried out:
Cyclosporine [INN] (tablets of 25, 50 and 100 mg sandimmunneoral) orally at 5 mg/kg/day for 6 weeks, if ineffective, the dose is increased to 7 mg/kg/day, the drug is used for another 4 weeks. When stopping the inflammatory process, the maintenance dose is 3-4 mg / kg / day for 5-8 months;
Perhaps the combined use of cyclosporine with prednisolone: cyclosporine 5 mg / kg / day and prednisolone 0.2-0.4 mg / kg / day for 4 weeks, or cyclosporine 5 mg / kg / day and prednisolone 0.6 mg/kg/day for 3 weeks, or cyclosporine 7 mg/kg/day and prednisolone 0.2-0.4 mg/kg/day for 3 weeks, or cyclosporine 7 mg/kg/day and prednisolone 0.6 mg / kg / day for no more than 3 weeks. Maintenance dose of cyclosporine 3-4 mg/kg/day;
Azothioprine [INN] inside 1.5-2 mg / kg /;
Methotrexate [INN] orally at 7.5-15 mg/week - in the treatment of anterior uveitis, mydriatics are prescribed, which are installed in the conjunctival sac 2-3 times a day and / or administered subconjunctivally at 0.3 ml: atropine [INN] (1 % eye drops and 0.1% injection), phenylephrine [INN] (2.5 and 10% irifrin eye drops or 1% mezaton injection);
To reduce the effects of fibrinoid syndrome, fibrinolytic drugs are used;
Urokinase [INN] is administered under the conjunctiva at 1250 IU (in 0.5 ml) 1 time per day, lyophilized powder to prepare a solution of 100,000 IU. For subconjunctival administration, the contents of the ex tempore vial are dissolved in 40 ml of solvent;
Recombinant prourokinase [INN] is injected subconjunctiva and parabulbarno at 5000 IU/ml (hemase). For an injection solution, the contents of the ex tempore ampoule are dissolved in 1 ml of saline;
Collalysin [INN] is injected under the conjunctiva at 30 IU. For an injection solution, the contents of the ex tempore ampoule are dissolved in 10 ml of a 0.5% solution of novocaine (collisin lyophilized powder, 500 IU in ampoules);
Histochrome [INN] 0.2% solution is administered subconjunctival or parabulbar;
Lidaza is administered at 32 units in the form of electrophoresis;
Wobenzym 8-10 pills 3 times a day for 2 weeks, then 2-3 weeks 7 pills 3 times a day, then 5 pills 3 times a day for 2-4 weeks, then 3 pills for 6 -8 weeks;
Phlogenzym 2 tablets 3 times a day for several months. Dragee taken 30-60 minutes before meals with plenty of water.
Also, to reduce the effects of fibrinoid syndrome, protease inhibitors are used:
Aprotinin [INN] is administered subconjunctivally and parabulbarno: Gordox in ampoules of 100,000 CIE (for subconjunctival administration, the contents of the ampoule are diluted in 50 ml of saline, 900-1500 CIE are injected under the conjunctiva);
Kontrykal lyophilized solution 10,000 CIE in vials (for subconjunctival administration, the contents of the vial are diluted in 10 ml of saline, 300-500 CIE are injected under the conjunctiva; for parabulbar administration, the contents of the vial are diluted in 2.5 ml of saline, 4000 CIE are injected under the conjunctiva);
Detoxification therapy: intravenous drip "hemodez" 200-400 ml, 5-10% glucose solution 400 ml with ascorbic acid 2.0 ml;
Desensitizing drugs: intravenous 10% calcium chloride solution, loratadine [INN] for adults and children over 12 years of age, 10 mg once a day orally, for children 2-12 years old, 5 mg once a day - claritin;
Etiological antimicrobial therapy depends on the cause of the disease.
Syphilitic uveitis: benzathine benzylpenicillin (retarpen) IM 2.4 million units 1 time in 7 days, 3 injections, benzylpenicillin novocaine salt IM 600,000 units 2 times a day for 20 days, benzylpenicillin sodium salt 1 million every 6 hours within 28 days. In case of intolerance to benzylpenicillin, doxycycline 100 mg orally 2 times a day for 30 days, tetracycline 500 mg 4 times a day for 30 days, erythromycin at the same dose, ceftriaxone IM 500 mg / day for 10 days , ampicillin or oxacillin intramuscularly 1 g 4 times a day for 28 days.
Toxoplasmosis uveitis: a combination of pyrimethamine [INN] (chloridine) orally 25 mg 2-3 times a day and sulfadimezin 1 g 2-4 times a day is used. Spend 2-3 courses for 7-10 days with breaks of 10 days. It is possible to use the combined preparation fansidar (F. Hoffmann La Roche), which contains 25 mg of pyrimethamine and 500 mg of sulfodoxine). This drug is used inside 1 tab. 2 times a day after 2 days for 15 days or 1 tab. 2 times a day 2 times a week for 3-6 weeks. With the / m administration of 5 ml of the drug is administered 1-2 times a day after 2 days for 15 days. Pyrimethamine is used in place with folic acid preparations (5 mg 2-3 times a week) and vitamin B12. Instead of pyrimethamine, aminoquinol can be used orally at 0.1-0.15 g 3 times a day.
Antibiotics of the lincosamine group (lincomycin and clindamycin) and macrolides (spiramycin) are used. Lincomycin [INN] is used subconjunctival or parabulbarno 150-200 mg, IM 300-600 mg 2 times a day or orally 500 mg 3-4 times a day for 7-10 days. Clindamycin [INN] is used subconjunctival or parabulbarno 50 mg 5 days daily then 2 times a week for 3 weeks, IM 300-700 mg 4 times a day or orally 150-400 mg 4 times a day for 7-10 days. Spiramycin [INN] IV slowly 1.5 million IU 3 times a day or orally 6-9 million IU 2 times a day for 7-10 days.
Tuberculous uveitis: in severe active uveitis, a combination of isoniazid [INN] is used for the first 2-3 months (300 mg orally 2-3 times a day, IM 5-12 mg/kg/day in 1-2 injections, subconjunctival and parabulbarno 3% solution is administered) and rifampicin [INN] (450-600 mg orally 1 time per day, intramuscularly or intravenously at 0.25-0.5 g per day), then for another 3 months, combined therapy with isoniazid and ethionamide [INN] (orally, 0.5-1 g per day in 2-3 divided doses).
With primary uveation of moderate severity a combination of isoniazid and rifampicin is used for the first 1-2 months, then for 6 months a combination of isoniazid and ethionamide or streptomycin [INN] is used (0.5 g orally 2 times a day for the first 3-5 days, and then 1 0 g 1 time per day, subconjunctival or parabulbar injection of a solution containing 50,000 IU / ml).
For chronic uveitis use a combination of isoniazid with rifampicin or ethionamide, streptomycin, kanamycin and glucocorticosteroids.
Viral uveitis: for infections caused by the herpes simplex virus, use acyclovir [INN] 200 mg orally 5 times a day for 5 days or valacyclovir [INN] 500 mg orally 2 times a day for 5-10 days. For infections caused by the Herpes zoster virus, use acyclovir [INN] orally 800 mg 5 times a day for 7 days or valaciclovir [INN] 1 g 3 times a day for 7 days. In severe herpetic infection, acyclovir is used in/in drip slowly at 5-10 mg/kg every 8 hours for 711 days or intravitreally at a dose of 10-40 mcg/ml.
In infections caused by cytomegalovirus, ganiclovir [INN] is used in / in slow drip at 5 mg / kg every 12 hours for 14-21 days, then maintenance therapy with ganciclovir is administered intravenously at 5 mg / ml daily for a week or every 6 mg/ml 5 days a week or orally 500 mg 5 times a day or 1 g 3 times a day.
Rheumatic uveitis: phenoxymethylpenicillin [INN] 3 million U/day in 4-6 injections for 7-10 days.
Uveitis in Reiter's syndrome: There are several ways to use antibiotics:
1. Reception within 1, 3 or 5 days.
2. Acceptance within 7-14 days.
3. Continuous use for 21-28 days.
4. Pulse therapy - 3 cycles of antibiotic therapy are carried out for 7-10 days with breaks of 7-10 days.
It is most advisable to use the following antibiotics:
Clarithromycin [INN] (by mouth 500 mg/day in 2 divided doses for 21-28 days;
Azithromycin [INN] - orally 1 g / day once;
Doxycycline [INN] - oral administration of 200 mg / day in 2 divided doses for 7 days. Children under 12 years of age are not recommended;
Roxithromycin [INN] - orally at 0.3 g / day in 1-2 doses, the course of treatment is 10-14 days;
Ofloxacin [INN] - adults, 200 mg orally once a day for 3 days. Children are not recommended;
Ciprofloxacin [INN] - for adults, 0.5 g / day orally on the first day, and then 0.25 g / day in 2 divided doses for 7 days. Children are not recommended.
Tumors of the vascular tract
Among malignant tumors of the vascular tract, melanoma or melanoblastoma is more common.
Melanoma arises mainly from pigmented spots - nevi. Tumor growth is activated during puberty, during pregnancy or in old age. Melanoma is thought to be caused by trauma. Melanoblastoma is a tumor of neuroectodermal origin. Tumor cells develop from melanocytes, Schwann cells of the sheaths of cutaneous nerves, capable of producing melanin.
The iris is affected in 3-6% of cases of melanoma of the vascular tract; the ciliary body - in 9-12% and the choroid - in 85% of cases.
Melanoma of the iris
It often develops in the lower parts of the iris, but it is possible in any other part of it. There are nodular, planar and diffuse forms. In most cases, the tumor is pigmented, dark brown in color; the nodular form of the tumor is more common in the form of a dark, well-defined spongy mass. The surface of the tumor is uneven, protrudes into the anterior chamber, and can displace the pupil.
Treatment: if the tumor spreads to no more than 1/4 of the iris, its partial removal (iridectomy) is indicated; with initial signs of tumor growth in the root of the iris, an iridocyclectomy should be performed. A small limited melanoma of the iris can be tried to destroy photo- or laser photocoagulation.
ciliary body melanoma
Initial tumor growth is asymptomatic. In the process of melanoma growth, changes appear associated with the mechanical effect of the tumor on adjacent tissues.
early symptom is a congestive injection in the system of anterior ciliary vessels, in a limited area, gonioscopically, the closure of the angle of the anterior chamber in a certain area is detected.
Paresis of the iris and contact clouding of the lens are noted. Sometimes melanoma is found in the angle of the anterior chamber as a dark formation on the surface of the iris.
AT diagnostics help gonioscopy, biomicroscopy, diaphanoscopy, echo-ophthalmoscopy (B-method), MRI.
Treatment: small limited tumors of the ciliary body can be excised within healthy tissue with preservation of the eyeball. In large tumors, enucleation of the eye is indicated.
Melanoma of the choroid
Most often occurs at the age of 50-70 years. There are nodular - the most frequent and planar forms of the tumor. The color of melanoma of the choroid is black, dark or light brown, sometimes pinkish (the most malignant).
In the clinical picture of melanoma of the choroid, 4 stages are distinguished: I - initial, non-reactive; II - the development of complications (glaucoma or inflammation); III - germination of the tumor beyond the outer capsule of the eye; IV - generalization of the process with the development of distant metastases (liver, lungs, bones).
Clinic of the disease depends on the location of the tumor. Melanoma of the macular area early manifests itself as visual impairment (metamorphopsia, photopsia, decreased visual acuity). If melanoma is located outside the macula, then it remains asymptomatic for a long time. Then the patient complains of a dark spot in the field of vision.
Perimetry reveals a scotoma corresponding to the location of the tumor. With ophthalmoscopy, a tumor with sharp boundaries is visible in the fundus, protruding into the vitreous body. The color of melanoma is grayish brown to gray.
In stage I of the disease, the retina tightly fits the melanoma without wrinkling; no retinal detachment yet. Over time, secondary retinal detachment occurs, which masks the tumor. The appearance of a congestive injection and pain indicates the transition of the disease to stage II, i.e., secondary glaucoma begins to develop. A sudden subsidence of pain with a simultaneous decrease in intraocular pressure indicates that the process has gone beyond the eyeball (stage III). Metastases indicate the transition of the tumor to stage IV.
Treatment: enucleation; with the germination of melanoma - exenteration with X-ray therapy. With a tumor size of no more than 4-6 diameters of the optic nerve head and a distance of no more than 1.5 mm, transpupillary photo- or laser coagulation can be used. For postequatorial tumors no larger than 12 mm and prominence up to 4 mm, transpupillary thermotherapy (using high temperature) with an infrared laser with a wavelength of 810 nm is used.
Thermotherapy can be combined with brachytherapy. Transscleral brachytherapy (suturing of an applicator with strontium or ruthenium radionuclides, which give pure p-radiation) is performed with a maximum diameter of no more than 14 mm and a tumor thickness of no more than 5 mm. In some cases, cryotherapy is used.
Article from the book:
a) Anatomy of the uveal tract (choroid) of the eye. The uveal tract is formed by the iris, ciliary body, and choroid. The stroma of the iris is formed by pigmented and non-pigmented cells, collagen fibers and a matrix consisting of hyaluronic acid. Crypts differ in size, shape, and depth; their surface is covered with an inhomogeneous layer of connective tissue cells, fused with the ciliary body.
The different colors are determined by the pigmentation of the anterior boundary layer and the deep stroma: the stroma of blue irises is much less pigmented than that of brown irises.
The ciliary body performs the functions of producing aqueous humor, accommodation of the lens, and forms the trabecular and uveoscleral outflow tracts. It extends 6 mm from the root of the iris to the anterior zone of the choroid, the anterior section (2 mm) carries the ciliary processes, and the posterior part (4 mm) is flatter and more even - pars plana. The ciliary body is covered with an outer pigmented and inner non-pigmented epithelial layer.
The ciliary muscle consists of longitudinal, radial and circular portions. The ciliary processes are formed mainly from large fenestrated capillaries through which fluorescein seeps out and veins flowing into vorticose veins.
The choroid lies between the retina and sclera. It is formed by blood vessels and bounded internally by Bruch's membrane and an avascular suprachoroidal space externally. It has a thickness of 0.25 mm and consists of three vascular layers, receiving blood supply from short and long posterior and anterior ciliary arteries. The choriocapillary layer is the innermost layer, the middle layer is the layer of small vessels, the outer layer is the layer of large vessels. The vessels of the middle and outer layers of the choroid are not fenestrated.
Choriocapillary layer - a continuous layer of large capillaries, it lies under the retinal pigment epithelium and nourishes the outer parts of the retina; the endothelium of the capillaries is fenestrated, fluorescein seeps through it. Bruch's membrane consists of three layers: an outer elastic, a middle collagen layer, and an inner circular layer, the latter being the basement membrane of the retinal pigment epithelium. The choroid is tightly fixed at the margins, extending anteriorly to the dentate line, and joining the ciliary body.
b) Embryology of the uveal tract. The uveal tract develops from the neuroectoderm, neural crest, and mesoderm. The sphincter, dilator, and posterior iris epithelium develop from the neuroectoderm. Differentiation and pigment migration continue into the second and third trimesters. The smooth muscles of the iris, the choroidal stroma, and the ciliary body develop from the neural crest. The formation of the iris begins with the closure of the fetal fissure on the 35th day of gestation. The sphincter muscle appears at the edge of the eye cup at the tenth week of gestation, myofibrils are formed at 10-12 weeks.
The dilator is formed at 24 weeks of gestation. The neuroectoderm differentiates into both pigmented and non-pigmented epithelium of the ciliary body at 10-12 weeks of gestation. The smooth muscles of the ciliary body are present already in the fourth month of gestation, even before the formation of the stroma of the iris; it joins the ciliary sulcus in the fifth month. The formation of choroid pigment cells from neural crest cells is completed by birth. Blood vessels develop from the mesoderm and neural crest. The choroidal vasculature differentiates from mesenchymal elements in the second week of gestation and develops over the next 3–4 months.
The pupillary membrane disappears shortly before term delivery. At birth, the pupil is narrow, but as the dilator muscle develops, it dilates. The role of the ciliary muscle in accommodation increases between the third and sixth months of life. By the age of two, the length of the ciliary body reaches three-quarters of the length of the ciliary body of an adult. In representatives of all races, pigmentation is completed by the age of one; during the first year of life, the irises become darker, and never lighter.
(A) Structure of a normal eye. Note that the surface of the iris is very prominent with crypts and folds.(B) Schematic of normal aqueous humor flow. The aqueous humor formed in the posterior chamber flows through the pupil into the anterior chamber.
The main route of outflow of aqueous humor is through the trabecular meshwork into Schlemm's canal.
Additional pathways (uveoscleral and iris, both not shown) drain only a small amount of aqueous humor.
(A) Formation of the optic vesicle on the lateral wall of the diencephalon. The optic stalk connects the ophthalmic vesicle to the forebrain. (9.5 days of mouse gestation, corresponding to 26 days of human gestation). (B) Invagination of the optic vesicle and formation of the lens vesicle (onset 10.5 days of mouse gestation, corresponding to 28 days of human gestation).
(B) Invagination of the lens fossa, formation of a two-layered ophthalmic cup from the invaginated optic vesicle (end of 10.5 days of mouse gestation, corresponds to 32 days of human gestation).
(D) Closure of the embryonic choroidal fissure, formation of the lens vesicle and primary vitreous (12.5 days of mouse gestation, corresponding to 44 days of human gestation).
(E) Formation of the nerve fiber layer, migration of neural crest cells and formation of the lens nuclear belt (14.5 days of mouse gestation, corresponding to 56-60 days of human gestation).
(E) Eye at the end of the organogenesis stage. The cornea, the iris, the beginnings of the extraocular muscles and the lacrimal gland are clearly visible.
The arrows indicate the pupillary membrane (16.5 days of mouse gestation correspond to >60 days of human gestation).
