Allergic keratit – the inflammatory change of a cornea (cornea) of an eye connected with development of acute allergic reaction. Manifestations of an allergic keratit include a corneal syndrome (a photophobia, dacryagogue, ), the injection mixed conjunctival , surface infiltrates in a cornea. Diagnostics of an allergic keratit is based on data of external examination, check of visual acuity, biomicroscopy, an analgezimetriya, coloring of a cornea fluorestsiny, microscopy and crops of prints from a cornea, intracutaneous allergic tests etc. Treatment of an allergic keratit demands performing local therapy by corticosteroids, reception of antihistamines.
The cornea represents the forward part of an external cover of an eye located in an eye crack and is the most important element of the svetoprelomlyayushchy device. As the most important functions of a cornea serve protection of an eye against mechanical, thermal and other damages, hits of microorganisms and dust. Properties of a cornea – transparency, curvature of a surface, sphericity, structural and optical uniformity in define a condition of sight many. Inflammatory defeats of a cornea – a keratita often lead to irreversible changes of a cornea and permanent decrease in sight up to a total blindness.
In ophthalmology allergic keratit is considered as local manifestation of acute allergic reaction. Allergic keratita arise at children's and teenage age more often and proceed together with allergic conjunctivitis.
Classification of keratit
Are divided by an etiology of a keratita on bacterial (nonspecific and specific at tuberculosis, syphilis, malaria, a brucellosis), virus (adenoviral, herpetic, clumsy, ospenny), toksiko-allergic (fliktenulezny, skrofulezny, allergic), exchange, fungal, neurogenetic, post-traumatic, akantamebny, etc.
Depending on the influencing factors of a keratita are subdivided on exogenous (are caused by etiologichesky agents of the external environment) and endogenous (are caused by the internal reasons). Development of allergic conjunctivitis can be caused by both the exogenous, and endogenous reasons.
On extent of involvement of layers of a cornea distinguish the superficial keratita proceeding with damage of an epithelium and boumenovy membrane and deep keratita at which are involved in an inflammation Strom and a destsemetov a cornea membrane. On localization of a keratita can be peripheral, central; on prevalence degree - limited or diffusion.
Reasons of an allergic keratit
Allergic keratit can be caused various ekzo-and endoallergens. As exogenous allergens medicines (including vaccines), foodstuff, pollen of plants, hair of animals, household chemicals, cosmetics, etc. most often act. At the same time emergence of a medicinal and allergic keratit can be caused both by local applications of medicines, and their parenteral introduction.
Bacterial toxins in plaintive liquid, helminthic invasions, tubercular intoxication belong to endogenous allergens. Against the background of helminthoses, not only the clinic of an allergic keratit, conjunctivitis, a blefarit, iridotsiklit, but also atopic dermatitis, a pollinoz, bronchial asthma can develop. The special group is made by the tubercular and allergic keratita caused by tubercular intoxication. At this form of an allergic keratit of a mikobakteriya of tuberculosis are not found, however positive specific tubercular tests (reaction to Mant, test of the Tuberculine test) testify to a high sensitization of an organism.
At an allergic keratit puffiness and subepitelialny infiltration of a cornea is noted. Single or multiple infiltrates of a cornea are localized in different sites of a cover and at various depth, have various form and the sizes. In the field of infiltrate the cornea loses the gloss. At the superficial allergic keratita proceeding with involvement of an epitelialny layer, infiltrates can completely resolve. In case of interest of deeper corneal layers on the place of inflammatory focuses cicatricial fabric is formed, and there are more or less expressed sites of turbidity.
Allergic keratit is followed by expansion of vessels - conjunctival an injection; erosion and ulcerations of corneal fabric are quite often noted. Microscopic changes are characterized by a deskvamation and transformation of an epithelium, lymphocytic reaction of fabric, damage of a boumenovy membrane.
Symptoms of an allergic keratit
The clinical picture of an allergic keratit is characterized, the so-called corneal syndrome including a photophobia, plentiful dacryagogue, sharp narrowing of an eye crack ().
The irritation of the nervous terminations of a cornea at an allergic keratit leads to gripes and burning in an eye, to feeling of a foreign matter, constant pains because of which the patient cannot open eyes. There is a perikornealny or mixed conjunctival injection (reddening of an eyeball). In view of development of turbidity in an optical zone decrease in visual acuity is noted. After the termination of an allergic keratit, sight in most cases is not restored. Tubercular and allergic keratit proceeds with subfebrilitety, an indisposition.
At distribution of inflammatory reaction with an allergic component to an iris, to a skler or a ciliary body arise Irit, sklerit, iridotsiklit. The heavy or long current of an allergic keratit can lead to perforation of a cornea, secondary glaucoma, the complicated cataract, neuritis of an optic nerve, an endoftalmit.
Diagnostics of an allergic keratit
Ophthalmologic inspection at an allergic keratit includes survey of eyes, visual acuity check, biomicroscopy, the test of coloring of a cornea fluorestsiny, an analgezimetriya. For identification of allergen intracutaneous allergic tests are carried out. In case of accession of a secondary infection of the activator find by means of bacteriological dab research. For an exception of helminthoses investigate kcal on eggs of worms.
At suspicion on tubercular and allergic keratit the X-ray analysis of lungs or fluorography, tuberkulinovy tests is shown. Differential diagnostics of allergic keratit is carried out from keratita of a virus, fungal, bacterial etiology.
Treatment of an allergic keratit
At an allergic keratit the termination of contact with allergen and its elimination is necessary. Installations of 0,4% of solution of dexamethasone, a mortgaging of eye ointments are locally appointed (prednizolonovy, gidrokortizonovy); at a heavy allergic keratit - subconjunctival injections of dexamethasone. At chronic recidivous infectious and allergic keratita appoint long rates of steroid hormones inside.
As obligatory component of treatment of an allergic keratit serves reception of antihistamines (a hloropiramin, a mebgidrolin, a hifenadin, a klemastin, etc.), vitamins C and B2 (Riboflavinum), sedatives, calcium chloride inside or intravenously.
In case of stratification of a bacterial infection make instillations of solution of a sulfatsetamid, sulfapiridazin-sodium, a levomitsetin, a tetratsiklin of a hydrochloride and other antibacterial means. At identification of a helminthic invasion antigelmintny medicines are appointed.
Treatment of a tubercular and allergic keratit is carried out with participation of the phthisiatrician. The patient in addition appoints antitubercular therapy by streptomycin, an isoniazid, ftivazidy, etc.; are carried out physical therapy: electrophoresis of streptomycin, calcium, hydrocortisone, the general Ural federal district.
At decrease in visual acuity are shown and an electrophoresis with gialuronidazy. At cicatricial changes of a cornea the keratoplasty is made, at development of secondary glaucoma - surgical or laser treatment of glaucoma.
Forecast and prevention of an allergic keratit
Timely and rational therapy of a superficial allergic keratit leads to the fact that infiltrates of a cornea resolve completely or with the minimum consequences for sight. As a consequence of a deep keratit serves development of pomutneniye of a cornea, considerable decrease in visual acuity or its total loss.
Prevention of an allergic keratit consists in an exception of contact with allergens, expulsion of helminths of children, treatment of tubercular intoxication.