Allergic Keratitis

The range of allergic reactions and diseases of the cornea is less clearly delineated than the eye eye allergy allergy. The situation is complicated by the fact that the cornea is exposed not only to exo-and endoallergens, but also to allergens from its own tissue that arise when it is damaged.

[1], [2], [3], [4]

Causes of allergic keratitis

A classic example of the allergic process in the cornea is the phenomenon of Wessel: the development of marginal keratitis in an animal sensitized by the introduction of heterogeneous serum into the center of the cornea.

The clinic is close in its pathogenesis to the phenomenon of Wessel reaction occurs in the cornea with its burns, although it is caused by autoallergens. The layering of auto-allergy causes the extension of the zone of damage beyond the area of the cornea exposed to the burning substance, which aggravates the severity of the burn. The relatedness of antibodies arising from burns of the cornea and skin served as the basis for creating an effective method for treating ocular burns with serum of burned reconvalescent agents.

The highest autoimmune organ specificity is found in the epithelium and endothelium of the cornea, damage of which can lead to the formation of antibodies in inflammation, trauma, surgery, and the subsequent allergic reactions worsen the course of these processes. The desire to reduce these adverse effects is one of the reasons for the tendency observed in modern eye surgery to spare as much as possible during corneal endothelium operations. Many ophthalmic surgeons, for example, due to ultrasound damage to the endothelium of the cornea, refrain from phacoemulsification of cataracts.

Allergic reactions of the cornea can be caused by essentially any exo-and endoallergens, to which only the eyes and ancillary apparatus react. Il exogenous allergens are of greatest importance for medicines. According to the scientists' observations, they caused a change in the cornea in 20.4% of patients with allergic eye allergy, with local applications causing mainly epithelial lesions (64.9%), and taking drugs or injecting them leads to stromal keratitis (13, 4%).

Epitheliopathy of the cornea, its central erosion, epithelial, filamentous, stromal and marginal keratitis, according to the classification of these authors, represent the main clinical forms of the drug allergy of the cornea. With this allergy, the reactions of the cornea to other allergens, in particular pollen of plants, cosmetics, chemicals, etc., are very similar in many respects. In such patients, the point subepithelial infiltrates of the cornea, its erosion, prilimbal opacities and ulceration of the corneal tissue are often detected. Even with mild manifestations of the disease, the changes and desquamation of the epithelium are detected histologically, in places the Bowman membrane and the lymphocytic reaction of the tissue are absent. The detection of such, often mild, changes in the clinic is helped by staining the cornea (fluorescein, fuscin) and biomicroscopy.

[5], [6], [7], [8], [9], [10]

Symptoms of allergic keratitis

Observed clinically allergic reactions of the cornea to exogenous allergens are usually limited by changes in its anterior layers: epithelium, the Bowman membrane, superficial layers of the stroma suffer. More often such lesions are complications of allergic diseases of the eyelids and conjunctiva. For example, eczema of Pillata's cornea begins with a pronounced serous abacterial conjunctivitis, to which bubble epithelial keratitis is attached, followed by deeper corneal infiltrates with simultaneous eczema of the skin.

Repeated contact of the cornea with the allergen is not always limited to avascular reactions. In patients with eczema, it is possible to develop a circular corneal pannus. With a pronounced ingrowth into the cornea of the vessels, there is an extremely rare congenital syphilitic parenchymal keratitis, at which antibodies to spirochaetes are formed, and the altered proteins of the cornea serve as antigens. Vascular is rosacea-keratitis, in the development of which now great importance is given to endocrine allergic factors, in particular testosterone.

Often defeat of the eye is a marginal allergic keratitis. It begins with the appearance of one or several gray chain surface infiltrates of elongated form located along the limbus. In the future, the intensity of infiltrates increases, they ulcerate, with a delay in recovery appearing coming from limbus surface vessels. In contrast to the catarrhal ulcer caused by the Morax-Laxenfold bacillus, there is no intact site between the infiltrate and the limb, and also the indentations along the limb with the swelling of the thinned posterior layers of the cornea. On the contrary, infiltrates of allergic genesis often differ in "volatility": after lasting several days in some areas, they disappear here to appear in other places. Irritation of the eye is pronounced. Treatment is similar to that of other allergic diseases of the cornea. In this pathology G. Gunther emphasizes the role of focal infection with its chronic foci in the paranasal sinuses, teeth, nasopharynx. The resulting microbial allergens cause superficial and ulcerous, less often parenchymal marginal and central inflammation of the cornea. Elimination of infectious foci leads to rapid healing of the eyes of such patients.

Treatment of allergic keratitis

Effective therapy of pronounced manifestation of eye allergy and its auxiliary apparatus requires local and general complex effects on the organism taking into account the diversity of etiological and pathogenetic factors, the complexity of pathogenesis, disorders of the endocrine, central and autonomic nervous systems. The most effective in treatment is the prevention of contact with the allergen, its elimination, often itself leading to a rapid recovery.

However, in a timely manner to identify and turn off the allergen is not possible in every patient. In such cases, without stopping the search for the cause of the disease, it is necessary to work on certain links of the pathogenetic chain of the allergic process in order to inhibit the formation, neutralize the antibodies or suppress the pathochemical phase of the allergy. We also need funds that increase the resistance of the body and reduce its allergic reactivity, normalizing metabolism, permeability of blood vessels, nervous and endocrine regulation.

The first task - the inhibition of the formation of antibodies and the reaction of the allergen-antibody - is decided by the appointment of desensitizing drugs, primarily steroid hormones. Glucocorticoids reduce the production of antibodies, reduce the permeability of capillaries, delay the disintegration of complex mucopolysaccharides, and have a pronounced anti-inflammatory effect. Most clearly, their therapeutic effect is manifested in allergic reactions of a delayed type.

In eye practice, these potent, serious side effects drugs are shown to patients who have allergies of the eye (whether it is an independent process or a complication of another pathology) is pronounced strongly and is difficult to treat. Usually, these are diseases of the eyeball. In allergic lesions of the eye auxiliary apparatus, it is recommended that steroid use be avoided whenever possible.

For the treatment of ocular manifestations of allergies, the most recommended installations are dexamethasone (0.4% solution) or adzonone 4-6 times a day, use in the form of ointment prednisolone, hydrocortisone and cortisone (0.5-1%), dexamethasone (0.1%) , in the severe course of the disease of injection of dexamethasone or dexazone into the conjunctiva, as well as intravenous administration 3-4 times a day of prednisolone (5 mg each), triamcinolone (4 mg each), dexamethasone (0.5 mg per reception), medrizone, fluoromethanol. Treatment, as a rule, is carried out by short courses with a gradual decrease in doses, calculated so that after 10-15 days, taking the drug inside can be canceled. The syndrome of "cancellation" with such courses, if manifested, is only a certain exacerbation of the eye disease requiring prolongation of glucotherapy for a short time.

Long-term courses of treatment (1.5-2 months and more) and higher doses of steroid hormones (up to 60-70 mg of prednisone per day at the beginning of treatment) are prescribed for patients with chronic, relapsing, more often infectious-allergic eye diseases, as well as for the treatment of sympathetic ophthalmia. In microdoses, dexamethasone (0.001% aqueous solution) Yu. F. Maichuk (1971) recommends the treatment of an allergic reaction in the syndrome of Sjögren, chronic conjunctivitis of unknown etiology. Virus lesions of the eye, etc. Since salicyl and pyrazolone preparations possess certain immunosuppressive properties, they are used in moderate doses for the treatment of allergic eye diseases, especially for allergies of the eyelids and conjunctiva, avoiding the appointment of corticosteroids. The similarity in the mechanisms of antiallergic action also causes the possibility of replacing steroids with these drugs in patients to whom they are contraindicated. Treatment is carried out in courses lasting 3-5 weeks.

In recent years, with positive results in allergic eye sufferings, special immunosuppressive agents are tested, mainly from the arsenal of chemotherapy of tumors.

Suppression of the pathochemical phase of the allergic reaction is mainly carried out by antihistamines, which have the greatest effect with immediate allergy. The quantity of these preparations is great. Most often, ophthalmologists use diphenhydramine (0.05 g 3 times per day), suprastin (0.025 grams 2-3 times per day), diprasine (0.025 grams 2-3 times daily), levomepromazine (Hungarian tizerzin at 0, 05-0,1 g 3-4 times a day), diazolin (0.1-0.2 g twice daily), tavegil (0.001 g twice daily), phencarol (0.025-0.05 g 3-4 times a day). Not having a hypnotic effect, the last three drugs are suitable for outpatient treatment. When choosing drugs, the main importance is their tolerability of patients; with a weak action of one tool is shown its replacement by another.

For local therapy of these drugs used: dimedrol in droplets. Depending on the patient's reaction, instillations of 0.2%, 0.5% and 1% solutions 2-3 times a day are prescribed. Drops are useful to patients not only with pronounced but also with weak manifestations of allergies of the conjunctiva and anterior part of the eyeball. The mechanism of action of antihistamines has not been studied sufficiently. It is believed that they block histamine on recipient cells, reduce vascular permeability, reduce capillaries, inhibit the formation of hyaluronidase, which promotes the spread of histamine. Importantly, they also have a noticeable anti-inflammatory effect.

LD Ldo distinguishes three stages of action of antihistamines in their long-term use:

1. therapeutic stage (maximum effect);
2. the stage of habituation (the effect of pet or it is weak);
3. stage of allergic complications (the appearance of hypersensitivity to the drug used in some patients).

This dynamic limits the course of treatment for 3-4 weeks and confirms the advisability of changing drugs due to addiction to them.

In addition to these drugs, histamine is inactivated and sensitivity is reduced by histoglobulin (a mixture of gamma globulin and histamine). It is administered subcutaneously to 1-3 ml 1 time in 2-4 days; all for a course of 4-10 injections. Significant improvement in the course of the disease is observed only after 1-2 months. It is not recommended to combine this remedy with corticosteroids.

In a complex treatment of severe manifestations of eye allergies, you can also include intravenous infusions of 0.5% novocaine solution drip by 150 ml per day for 8-10 days. In the dropper add 10 ml of 5% solution of ascorbic acid, and inside appoint rutin.

Of the means of the general effect on the body with the aim of mobilizing its protective mechanisms for controlling allergy in ophthalmology, calcium chloride is usually prescribed inside (5-10% solution 1 tablespoon 3-4 times a day after meals), less often intravenously (10% solution by 5-15 ml daily) or calcium gluconate inside (1-3 g 2-3 times a day). For the same purposes AD Ado et al. (1976) recommend sodium thiosulfate (30% solution of 5-10 ml intravenously, for a course of 7-10 injections). All these medicines are well combined with antihistamines.

Patients with ocular manifestations of allergies are also useful vitamins C and B ₂ (riboflavin), sedatives. Strictly obligatory are sanation of foci of infection, treatment of other general-somatic processes, normalization of mental status, sleep, etc. A predisposition to allergies, including the eye, decreases when the organism is hardened, physical education and sports. In this essentially consists and prevention of allergic diseases in general and eye allergy in particular.

A very difficult task is to treat eye patients suffering from polyvalent allergies, which often give a pronounced local and sometimes general reaction to the local application of almost any medication. Allergens for them can be even those same glucocorticoids and antihistamines, which treat allergies. In such cases it is necessary to cancel all medicines, kat; they were not needed for the treatment of the underlying disease, and then very carefully, preferably by staging preliminary samples, to select the tolerated medications.

Suppressing in one way or another allergic reactions, the ophthalmologist has no right to forget that at the same time the entire immune system of the body suffers, his protection against infectious and other agents worsens.

The specific desensitization of tuberculin, toxoplasmin and other antigens, which is difficult to implement in a wide practice, is also covered in detail by A. Ya. Samoilova, II Shpak, and others.

Depending on the nature of the allergic pathology of the eye, simultaneously with antiallergic therapy, mainly symptomatic treatment is performed with drying, disinfecting, astringent and other medications, appointing mydriatic or myotics, and so on.

In particular, with ocular manifestations of Quincke's edema, if it is not possible to identify and eliminate the allergen, then symptomatic treatment is carried out mainly antihistamines. Local use of diphenhydramine; his or other histamine drugs are prescribed orally. With severe symptoms of the disease, amidopyrine, brufen, aminocaproic acid (0.5 to 2.5-5 g, depending on age, are washed down with sweetened water). Treatment of complications is normal. Corticosteroids are usually not shown.

With severe allergic dermatitis and eczema, along with possible elimination of the allergen, symptomatic therapy is performed similarly to the one recommended above with Quincke's edema. The appointment of antihistamines in the complex of this therapy is shown, since mixed allergies can not be excluded from the slow-immediate, and sometimes only immediate, type. Calcium, sodium thiosulfate or magnesium thiosulfate preparations are also recommended. Corticosteroids are prescribed only to patients with very severe manifestations of the disease.

When maceration and wetting show drying lotions ("compresses") for 10-15 minutes 3-4 times a day with various solutions: 1-2% solution of boric acid, 1% resorcinol solution, 0.25% amidopyrine solution, 0.25 -0.5% solution of silver nitrate, 0.25% solution of tannin. Cork after softening them with sterile fish oil or olive oil is removed, cracks and deep efflorescence are cauterized pointwise 2 - 5% solution of silver nitrate. Treatment is non-detached (sunglasses). To reduce the maceration of the skin detachable from the eye apply disinfectant, astringent, vasoconstrictive drops, and at night - lubrication of the ciliary edge of the eyelids with ointment.

With the weakening of inflammatory phenomena, disinfecting ointments on an ocular basis without petrolatum and specially prepared salicylic-zinc paste are shown. Proprietary ointments of the type "Geocortop", "Sinalar", "Oxicort", "Dermatolone", "Lokakotei" and others are manufactured not taking into account the features of the tissues of the eye and its auxiliary apparatus, are suitable only for external use. Applying them to the skin of the eyelid 1-2 times a day for 1-2 shoe, Yu. F. Maychuk (1983) received an effect in those cases when other corticosteroids did not help.

In the treatment of contact allergic conjunctivitis and dermatoconjunctivitis, antihistamine preparations are ineffective, vasoconstrictors do not work. Such patients are shown disinfectants in drops, ointments or films (GLN), corticoids, calcium chloride or calcium gluconate in the interior, acetylsalicylic acid, amidopyrine, short courses of glucocorticoids in medium doses with prolonged illness.

In the treatment of spring catarrh, according to research, the most effective are glucocorticoids. Given their better tolerability at a young age, they are prescribed in drops 2-3 times a day during the entire period of exacerbation of the disease, and also used to prevent relapses before the onset of the warm season. Severe manifestations of the disease require supplementation of local corticosteroid therapy with general intermittent courses of treatment with these drugs in moderate doses. The effectiveness of treatment increases the cryoapplication of conjunctival and limbus proliferation, sometimes their excision. Along with steroids, calcium chloride or calcium gluconate, riboflavin, cromolia sodium (intal) are useful. 3-5% sodium bicarbonate 3-5 times a day, zinc sulfate with epinephrine, at times 0.1-0.25% solution of dicaine, etc., are added to reduce itching and liquefaction of secretion. During the remission period, patients are subject to follow-up and anti-relapse treatment, when relapses are treated out-patient or in the eye hospitals.

With the introduction of drugs or testing, the oculist can observe the most severe common manifestation of an allergy - anaphylactic shock. The patient with suspicion of shock, especially with obvious signs of it, immediately put in a strictly horizontal position. Intramuscularly inject 0.5 ml of 0.1% solution of adrenaline, dexamethasone (4-20 mg) or prednisone (0.5-1 mg per 1 kg of body weight), euphyllin (1-2 ml of a 2.4% solution) chic diprofylline (5 ml of a 10% solution) and dimedrol (5 ml of a 1% solution) or another antihistamine. With insufficient action, these and other anti-shock drugs are administered intravenously).