Trachoma

Trachoma is a specific, communicable, chronic, infectious, usually bilateral, inflammation of the connective shell of the eyes, expressed by diffuse infiltration of it with the formation of follicles (grains), their degeneration, decay and subsequent scarring.

Epidemiology

Currently, around 400 million people worldwide suffer from trachoma and there are between 4 and 5 million people who are blind from trachoma. It occurs mainly in Africa, the Middle East, Asia, Central and South America, especially in areas with overpopulation and lack of sanitation.

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Causes of the trachoma

The causative agent of trachoma is Chlamydia trachoma A, B, C, discovered in 1907 by Provaczek and Halberstedter. Chlamydia are obligate intracellular parasites. Trachoma is transmitted from the eye to the eye through contaminated hands or common objects (towels). Flies also play an important role in the transmission of infection.

The incubation period of trachoma lasts from 5 to 12 days. The main essence of conjunctival disease in trachoma is the formation of follicles and infiltration, a characteristic feature is the development of scarring in the conjunctiva, which is inevitable for typical trachoma, at the site of infiltration and follicles. The disappearance of infiltration and the transformation of follicles into scar tissue trachoma ends. Trachoma affects only the connective shell of the eyes and is not localized on other mucous membranes. In the experimental study of trachoma in animals, it was not possible to obtain a typical trachoma on the conjunctiva of even anthropoid apes.

[8], [9], [10], [11], [12]

Symptoms of the trachoma

Trachoma proceeds chronically. Usually it begins imperceptibly, with insignificant mucopurulent discharge from the conjunctival cavity, sometimes accompanied by itching, photophobia, lacrimation, pseudoptosis (due to edema of the eyelids). The process is usually bilateral, more pronounced in the conjunctiva of the upper transitional fold of the upper eyelid.

Symptoms vary, depending on the degree of severity of infiltration, grains and papillae, as well as from concomitant complications. Nevertheless, it is possible to divide the course of trachoma into 4 stages.

For trachoma, the distribution of the process to the cornea is characteristic. In the surface layer of the upper limb (limbus) of the cornea, small point infiltrates appear, to which thin loops of conjunctival vessels approach. In this case, patients develop lacrimation, photophobia, blepharospasm. The initial signs of corneal trachoma can appear already in its earliest stages, which is of great importance in diagnosis. Often, especially with early treatment, the damage to the cornea by trachoma can be limited to this. When there is a reabsorption of infiltrates, the eyes calm down, but the network of thin surface vessels remains for life.

With a more severe course, a number of new infiltrates may occur, but already below the place where the vessels have grown. Infiltrates can spread down the horny fringe, merge with each other, forming a diffuse surface opacity of the cornea, which is penetrated by the vessels. The epithelium of the cornea over the opacity becomes uneven and rough. This superficial vascular inflammation of the cornea is called pannus (from the Greek pannus - "curtain").

Usually, the pannus descends downward to the cornea, reaches its center and abruptly terminates, but it can spread further to the entire cornea. The degree of infiltration of the cornea and the development of vessels in it are quite different for pannus. There are 2 forms of pannus: a thin pannus, in which there is a slight and hardly expressed vascularized infiltration of the cornea; vascular pannus, in which the cornea due to significant infiltration and an abundance of newly formed vessels takes the form of fleshy growths and is therefore called "sarcomatous pannus".

Trachomatous pannus occurs in any stage of trachoma, regardless of the severity and prevalence of the process in the conjunctiva. The emergence of trachomatous pannus is possible by the affected conjunctiva of the eyelids with the oral membrane or as a result of the spreading of the conjunctiva process of the eyeball on the cornea. Trachomatous pannus, depending on its prevalence, the nature and extent of corneal changes, reduces vision. Pannus has a great propensity to recur. The defeat of the cornea is an almost constant companion of trachoma and serves as an important differential diagnostic feature, especially the weight of the initial stage, when there are no signs of scarring yet. Therefore, when suspicion of trachoma should be very carefully examine the upper limb with a magnifying glass.

As already noted, in most cases trachoma begins imperceptibly and develops gradually and slowly. Often patients, without experiencing special suffering, do not seek medical help for a long time, not knowing what the disease threatens them in the future. In this case, patients are a source of contamination of others. Often, such patients seek help only when they have purulent discharge from the eyes or when they begin to lose their sight.

Patients seeking help at the very beginning of the disease, when one can see the initial forms of trachoma described above, complain of feeling in the eye of a foreign body, heat, burning, the appearance in the morning of mucous separated and glued eyelashes.

In contrast, some patients, despite the presence of signs of flowering trachoma and even a far-reaching process of scarring, do not experience any unpleasant sensations. These patients are identified during preventive examinations of certain groups of the population and especially schoolchildren, since trachoma in children usually proceeds much more easily than in adults. The question of the possibility of an acute onset of trachoma, when the disease begins with acute inflammatory phenomena in the presence of photophobia, lacrimation, severe pains and a large amount of purulent discharge, is debatable; then all these acute phenomena disappear, and follicles and infiltration, that is, signs of the first stage of the trachoma, come to the fore. Then the disease proceeds in the usual chronic form. A number of scientists categorically deny the possibility of acute trachoma, believing that in these cases any accompanying infection (Koch-Wilks sticks, very frequent with trachoma, pneumococci, etc.) is attached to the usual trachoma.

Stages

The first stage of trachoma in the initial phase has a pronounced infiltration of the mucous membrane of the eyelids and the development of follicles only in the transitional folds: in the developed form, diffuse infiltration and follicles spread to the cartilage, especially to the upper eyelid. All phenomena gradually increase, but signs of scarring are completely absent. The first stage of trachoma can exist for months, years.

The second stage of trachoma is the further development of mature juicy follicles, which are similar to lepidum raspberries; pannus and infiltrates in the cornea; appearance of individual scars of conjunctiva due to necrosis of follicles. However, at this stage, hypertrophy phenomena predominate over scarring phenomena, patients at this stage are most dangerous as a source of new infections, as overgrown follicles easily cover and their contents flow out. With a gradual decrease in inflammation (hyperemia, infiltration of follicles) and the growth of scarring, the trachomatous process passes into the third stage.

The third stage of trachoma is a common scarring of the conjunctiva with a combination of residual phenomena of inflammatory infiltration and follicles. In the scar-altered conjunctiva, separate areas of reddening and infiltration are also visible. The third stage of trachoma lasts a long time and can often be accompanied by exacerbations of the inflammatory process of phenomena and complications. At this stage, the effects of trachoma are already evident.

The fourth stage of trachoma is the final scarring of the conjunctiva without inflammatory processes: hyperemia and visible infiltration. Conjunctiva has the form of a whitish, as if a tendon surface, since it is replaced with a scar tissue in whole or in part in the form of a grid and small strokes. The fourth (cicatricial) stage of trachoma determines clinical recovery (but the presence of deep infiltration is not always easy to exclude). This stage of trachoma is not contagious, unlike the first three, which can last for years.

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Complications and consequences

The consequences of trachoma are manifold. Replacement of infiltrates and follicles with connective tissue leads to cicatricial degeneration of the conjunctiva, as a result of which the transitional folds are shortened; Reduced or destroyed vaults, which limits the movement of the eyeball. When pulling the eyelid, especially the lower one, you can see how the conjunctiva is stretched in the form of vertically extending folds (simblepharon).

Scarring changes in the thickness of the cartilage and conjunctiva leads to contraction and, as a result, to trough curvature of the cartilage, which subsequently causes the eyelid turning. In this case, the ciliary edge of the eyelid, facing the cornea, constantly irritates and traumatizes it.

Along with a twisting, and sometimes independently there is a trichiasis - an incorrect position of eyelashes. Eyelashes - all or part of them - are directed towards the eyeball when the torn cornea flashes, causing her irritation. The development of trichiasis is associated with the spread of trachoma to the edge of the century, when the inflammatory infiltration is replaced by a connective tissue and the scars disrupt the correct position of the hair follicles. Scarring of the edge of the eyelids also leads to the closure of the excretory ducts of the meybolic glands, their cystic extension and thickening of the cartilage.

With the widespread scarring of the conjunctiva, its glandular apparatus dies, the excretory ducts of the lacrimal glands are closed, the conjunctiva and the cornea humidify and diminish, their sensitivity decreases, and metabolic processes are sharply disturbed. As a result, separate matte-white dry plaques appear on the conjunctus; the same plaques are formed on the cornea, the epithelium becomes thicker, keratinizes, acquires the character of the epidermis. The cornea becomes turbid, becomes opaque, and vision drops sharply. This condition is called a deep parenchymal xerosis.

The course of chronic trachomatous process can be complicated by acute inflammatory processes in conjunctiva, cornea and lacrimal organs.

Acute infectious conjunctivitis is a frequent complication of trachoma and is caused by microorganisms such as Koch-Weeks stick, pneumococcus, gonococcus.

Infections, layered on the trachomatous process, weighed its course and changed the picture of trachoma, creating difficulties in its diagnosis. Complication of trachoma with acute conjunctivitis promotes the spread of trachoma and presents a great danger to the cornea.

A serious complication of trachoma are ulcers of the cornea. In some cases this is typical of trachoma ulcers, in other cases the ulcer develops at some distance from it on any part of the cornea. Ulcers can spread in breadth and in depth and sometimes lead to corneal perforation at the site of the ulcer. In the future, a dense opaque leukoma (leukoma) forms, causing a sharp drop in vision and often blindness. The development of the ulcer is favored by the rubbing of the eyelashes along the cornea and the twisting of the eyelids, which is often the case with trachoma.

Often, with trachoma, a chronic inflammation of the lacrimal sac arises, as a result of which tearing from the conjunctival sac to the nasal cavity is disrupted and panic conjunctivitis develops. This adversely affects the course of trachoma.

The course of trachoma is long. It takes months, years, sometimes all my life. The main significance in the course of trachoma is the general state of the organism, its reactivity. Trachoma becomes more stubborn and difficult to treat in those who suffer from such common diseases as tuberculosis, scrofula, malaria, helminthic invasion. Common diseases, reducing the reactivity of the body, weighed down the flow of trachoma.

Easier and less noticeable trachoma occurs in children. It is in children that spontaneous cures are more often observed without particularly severe changes in the conjunctiva.

[16], [17], [18], [19], [20],

Diagnostics of the trachoma

Diagnosis of trachoma is based on a characteristic clinical picture and laboratory findings such as the predominance of polymorphonuclear leukocytes in conjunctival scrapings, the detection of intrapposic inclusions (Provacek-Halberstedter bodies) in epithelial cells of conjunctival scrapings, the detection of chlamydial particles in conjunctival scrapings in immunofluorescence using monoclonal antibodies .

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Treatment of the trachoma

Chemotherapy is the long-term local and general use of antibiotics and sulfonamides, which act on the causative agent of trachoma and eliminate the concomitant bacterial flora. When trachoma, two methods of treatment are used: continuous and intermittent.

Continuous treatment of trachoma is included in the appointment of topical ointments of antibiotics (1% tetracycline, 0.5% erythromycin ointment) 3 times a day for 2 months and sulfonamides (5% etazol ointment, 10% solution of sulfacyl sodium ) 3 times a day for 1.5 months.

When intermittent treatment of trachoma is recommended the use of antibiotics prolonged action (dibiomycin, ditetracyclipa, dimethylchlorotetrapiplin) in the form of 1% ointment 2 times 5 consecutive days monthly for 6 months. Antibiotics and sulfonamides are administered internally in severe forms of trachoma for 1 week (tetracycline, erythromycin 250 mg 4 times daily, doxycycline 1.5 mg / kg 1 time per day). Rare, no more than 2-3 times during the course of treatment with antibiotics and sulfonamides, expression of follicles. Trachomatous grains are squeezed out. For extrusion, use the tweezers Bellyarminova. With abundant detachable and ulcer of the cornea, the expression is prepared, as before the operation. The operator wears glasses so that the patient that is separated from the eyes does not get into his eyes. Anesthesia is carried out - twice instillation into the conjunctival cavity of 0.5% solution of dicaine or 1 ml of 1% solution of novocaine. After expression, the eyes are washed with a solution of potassium permanganate (1: 5000) and the ointment of antibiotics is laid. This type of treatment of trachoma is called combined. It is most effective.

The success of trachoma treatment depends on the early recognition of the disease, the timeliness of the onset and activity of treatment, taking into account the general condition and individual characteristics of the patient with trachoma.

The main tasks that the doctor faces in the treatment of trachoma is to:

• trachoma is contagious, with detachable, make non-contagious;
• transfer the active stage of trachoma to regressive as soon as possible;
• to limit the process of scarring;
• prevent the development of complications, especially from the side of the cornea;
• increase the protective properties of the body.

Trachoma is spreading where the sanitary culture of the population is low; Bad socio-economic conditions also contribute to the spread of the disease. Therefore, in the complex of preventive measures to combat trachoma, active sanitary and enlightening work is important