Keratita – group of inflammatory defeats of a cornea - a forward transparent cover of an eye, having various etiology, causing turbidity of a cornea and decrease in sight. For a keratit it is typical, the so-called corneal syndrome which is characterized by dacryagogue, a photophobia, blefarospazmy; feeling of a foreign matter of an eye, the cutting pains, change of sensitivity of a cornea, decrease in sight. Diagnostics of a keratit includes carrying out biomicroscopy of an eye, test with fluorescein, a cytologic and bacteriological research of dab from a conjunctiva and a cornea, statement of immunological, allergologichesky tests. At identification of a keratit treatment is carried out etiotropny (antiviral, antibacterial, antiallergic etc.). At ulcerations of a cornea microsurgical intervention (keratoplasty) is shown.
Inflammatory diseases of an eye are the most frequent pathology in ophthalmology. The greatest group among them is made by conjunctivitis (66,7%); inflammatory defeats of a cornea – a keratita meet in 5% of cases. At a conjunctival cavity of an eye constantly there is microflora which even at the minimum damage of a cornea easily causes its inflammation. In half of cases the permanent decrease in sight demanding application of microsurgical techniques for restoration of optical properties of a cornea becomes a consequence of a keratit, and in some cases the current of a keratit can lead to an irreversible blindness. Development of a purulent ulcer of a cornea at a keratita in 8% of cases is followed by anatomic death of an eye and in 17% - demands an eyeball enukleation in connection with unsuccessfulness of conservative treatment.
Reasons of keratit
The greatest number of cases of development of a keratit is connected with a virus etiology. In 70% of observations as activators viruses of simple herpes and herpes the Eelgrass (the surrounding herpes) act. To provoke development of a keratit, especially at children, the adenoviral infection, measles, chicken pox also can.
The following big group of keratit is made by the purulent damages to a cornea caused by bacterial nonspecific flora (a pneumococcus, a streptococcus, staphylococcus, a diplococcus, a sinegnoyny stick, colibacillus, klebsiyelly, Proteus) and specific causative agents of tuberculosis, salmonellosis, syphilis, malaria, brucellosis, clamidiosis, gonorrhea, diphtheria etc.
The severe form of a keratit is caused by an amoebic infection - Acanthamoeba bacterium; amoebic keratit often arises at the people carrying contact lenses and in the long term can end with a blindness. Activators of a mycotic keratit (keratomikoz) are fungi , aspergilla, Candida.
Keratit can serve as manifestation of local allergic reaction at pollinoza, use of some medicines, a helminthic invasion, hypersensibility to foodstuff or pollen of plants. Immune and inflammatory defeat of a cornea can be observed at rheumatoid arthritis, a nodular periartrit, Shegren's syndrome, etc. diseases. At intensive impact on eyes of ultra-violet radiation can develop fotokeratit.
In most cases emergence of a keratit is preceded by a mechanical, chemical, thermal trauma of a cornea, including intraoperative damage of a cornea when carrying out eye operations. Sometimes keratit the century (blefarita), mucous eyes (conjunctivitis), a plaintive bag (dakriotsistit) and plaintive tubules (kanalikulit), sebaceous glands of a century (meybomit) develops as a complication of a lagoftalm, inflammatory diseases. To one of common causes of a keratit serves non-compliance with rules of storage, disinfection and use of contact lenses.
Distinguish exhaustion, a lack of vitamins from the endogenous factors favoring to development of a keratit (And, B1, B2, C, etc.), decrease in the general and local immune responsiveness, disorder of exchange (diabetes, gout in the anamnesis).
Patomorfologichesky changes at keratita are characterized by hypostasis and infiltration of corneal fabric. The infiltrates formed by polynuclear leukocytes, gistiotsita, lymphoid and plasmatic cages have various size, the form, color, indistinct borders. In a stage of permission of a keratit there is a cornea neovaskulyarization - germination in a cover of neogenic vessels from a conjunctiva, regional looped network or both sources. On the one hand, the vaskulyarization promotes improvement traffic of corneal fabric and to acceleration of recovery processes, with another – neogenic vessels zapustevat further and reduce transparency of a cornea.
At a heavy current of a keratit the necrosis, microabscesses, cornea ulcerations develop. Ulcer defects in a cornea cicatrize further, forming a cataract (leyky).
Classification of keratit
Keratita courses of inflammatory process, depth of defeat of a cornea, an arrangement of inflammatory infiltrate and other signs are classified depending on an etiology.
Depending on depth of defeat distinguish superficial and deep keratita. At a superficial keratit about 1/3 thickness of a cornea (an epithelium, the top stromalny layer) are involved in an inflammation; at a deep keratit – all of Strom.
On localization of infiltrate of a keratita happen central (to an infiltrate arrangement in a pupil zone), paracentral (to infiltrate in an iris belt projection), and peripheral (to infiltrate in a limb zone, in a projection of a tsiliarny belt of an iris of the eye). Than tsentralny infiltrate is located, from that visual acuity suffers during a current of a keratit and in its outcome stronger.
By etiologichesky criterion of a keratita subdivide on exogenous and endogenous. Carry an erosion of a cornea, keratita of traumatic, bacterial, virus, fungal genesis, and also the keratita caused by defeat a century, conjunctivas and meybomiyevy glands to exogenous forms (meybomiyevy keratit). Infectious defeats of a cornea of a tubercular, syphilitic, malarial, brutsellezny etiology are among endogenous keratit; allergic, neurogenetic, hypo - and avitaminous keratita. Endogenous keratita of not clear etiology include nitchaty keratit, the corroding cornea ulcer, rozatsea-keratit.
Symptoms of a keratit
The general manifestation characteristic of all forms of a disease, the corneal syndrome developing at a keratita serves. At the same time there are sharp eye pains, intolerance of bright day or artificial light, dacryagogue, an involuntary smykaniye a century (reflex ), deterioration in sight, feeling of a foreign matter under a century, a perikornealny injection of an eyeball.
The corneal syndrome at a keratita is connected with irritation of the sensitive nervous terminations of a cornea the formed infiltrate. Besides, owing to infiltration transparency and gloss of a cornea decreases, its turbidity develops, sphericity and sensitivity is broken. At a neurogenetic keratit sensitivity of a cornea and expressiveness of a corneal syndrome, on the contrary, are reduced.
At a congestion of lymphoid cages infiltrate gets a grayish shade; at prevalence of leukocytes its color becomes yellow (purulent infiltrate). At superficial keratita infiltrate can resolve almost completely. In case of deeper defeat on the place of infiltrate corneas, various on intensity of turbidity, which can reduce visual acuity in different degree are formed.
The adverse option of development of a keratit is connected with formation of ulcerations of a cornea. Further, during the flaking and a slushchivaniye of an epithelium, the superficial erosion of a cornea is formed in the beginning. Progressing of rejection of an epithelium and a necrosis of fabrics leads to formation of an ulcer of the cornea having a defect appearance with the muddy gray bottom covered with exudate. Regress of an inflammation, clarification and an epitelization of an ulcer, the scarring of a stroma leading to turbidity of a cornea – to formation of a cataract can be an outcome of a keratit at an ulcer of a cornea. In hard cases deep ulcer defect can get into the forward camera of an eye, causing education to a destsemetotsela - hernias of a destsemetovy cover, an ulcer perforation, formation of forward sinekhiya, development of an endoftalmit, secondary glaucoma, the complicated cataract, neuritis of an optic nerve.
Keratita quite often proceed with a simultaneous inflammation of a conjunctiva (keratokonjyunktivit), skler (keratosklerit), a vascular cover of an eye (keratouveit). Quite often also develop Irit and iridotsiklit. Involvement in a purulent inflammation of all covers of an eye leads to death of an organ of vision.
Diagnostics of a keratit
In diagnostics of a keratit its communication with the postponed general diseases, viral and bacterial infections, an inflammation of other structures of an eye, eye microinjuries etc. is important. At external examination of an eye the ophthalmologist is guided by expressiveness of a corneal syndrome and local changes.
As the leading method of objective diagnostics of a keratit serves the eye biomicroscopy during which character and the amount of defeat of a cornea is estimated. Thickness of a cornea is measured by means of an ultrasonic or optical pakhimetriya. For the purpose of assessment of depth of defeat of a cornea at a keratita the endotelialny and confocal microscopy of a cornea is carried out. Studying of curvature of a corneal surface is carried out by carrying out a computer keratometriya; a refraction research – by means of a keratotopografiya. For definition of a kornealny reflex resort to test for sensitivity of a cornea or esteziometriya.
For the purpose of detection of erosion and ulcers of a cornea performance of flyuorestseinovy instillyatsionny test is shown. When drawing on a cornea of 1% of solution of a flyuorestsein of sodium, the erozirovanny surface is painted in greenish color.
An important role for definition of medical tactics at a keratita is played by bacteriological crops of material from a bottom and edges of an ulcer; cytologic research of a buccal swab of a conjunctiva and cornea; PTsR, mutual fund, IFA-diagnostics. If necessary allergologichesky, tuberkulinovy tests etc. are carried out.
Treatment of a keratit
Treatment of a keratit has to be carried out under observation of the ophthalmologist in a specialized hospital within 2-4 weeks. The general principles of pharmacotherapy of keratit include local and system etiotropny therapy with application antibacterial, antiviral, antifungal, etc. medicines.
At virus keratita for the purpose of suppression of the revealed infection local instillations of interferon, an acyclovir are applied; a mortgaging of ointments (tebrofenovy, florenalevy, bonaftonovy, with an acyclovir). Parenterally and inside appoint immunomodulators (medicines of a timus, ).
Bacterial keratita demand prescription of antibiotics taking into account sensitivity of the activator to them in the form of eye drops, parabulbarny and subconjunctival injections, in hard cases – by parenteral introduction of penicillin, tsefalosporin, aminoglycosides, ftorkhinolon.
Treatment of a tubercular keratit is carried out under the leadership of the phthisiatrician, using antitubercular himiopreparata. At an allergic keratit antihistamines, subconjunctival introduction and instillations of hormonal medicines are appointed. In case of a syphilitic or gonorrheal keratit specific therapy under observation of the venereologist is shown.
At keratita of various etiology for the purpose of prevention of secondary glaucoma local application of midriatik (atropine of sulfate, a skopolamin) is shown; for stimulation of an epitelization of defects of a cornea - a taurine instillation, putting the healing ointments etc. At decrease in visual acuity appoint and an electrophoresis with enzymes.
Ulcerations of a cornea are the basis for carrying out microsurgical interventions: mikrodiatermokoagulyation, lazerkoagulyation, defect cryoapplications. In case of sharp decrease in sight and in view of cicatricial turbidity of a cornea holding an eksimerlazerny procedure of removal of superficial hems or a keratoplasty is shown. At development against the background of a keratit of secondary glaucoma laser or surgical treatment of glaucoma is shown. At heavy keratita the eyeball enukleation can be required.
Forecast and prevention of keratit
The outcome and consequences of a keratit considerably depend on an etiology of defeat, character and localization of infiltrate, the accompanying complications. Timely and rational therapy of a keratit lead to a traceless rassasyvaniye of infiltrates of a cornea or formation of easy pomutneniye like a cloudlet. At the deep keratita in particular complicated by a cornea ulcer and also at the paracentral and central arrangement of infiltrate, develop turbidity of a cornea of various degree of expressiveness.
The cataract, secondary glaucoma, atrophy of an optic nerve, atrophy of an eyeball and total loss of sight can become an outcome of a keratit. Septic complications in the form of thrombosis of a cavernous bosom, phlegmon of an eye-socket, sepsis are especially menacing for life.
Prevention of keratit includes the prevention of injuries of eye, timely detection and treatment of conjunctivitis, blefarit, a dakriotsistit, somatic diseases, the general infections, allergies, etc.