Syndrome of a dry eye
Syndrome of a dry eye (kseroftalmiya) – a condition of insufficient moisture content of a surface of a cornea and a conjunctiva owing to violation of quality and amount of plaintive liquid and instability of a plaintive film. As manifestations of a syndrome of a dry eye serve burning and gripes, feeling of sand in eyes, dacryagogue, a svetofobiya, bystry exhaustion during the visual work, intolerance of dry and dusty air. The syndrome of a dry eye is diagnosed by results of biomicroscopy, Shirmer and Norn's tests, flyuorestseinovy instillyatsionny test, a tiaskopiya, osmometriya, crystallography of plaintive liquid, a cytologic research of dab from a conjunctiva. As treatment of a syndrome of a dry eye medicines of an artificial tear, an obturation of slezootvodyashchy ways, a tarzorafiya, a keratoplasty, transplantation of salivary glands are shown.
Syndrome of a dry eye
The syndrome of a dry eye is quite frequent state in ophthalmology of which deficiency of moistening of a surface of a cornea and conjunctiva of an eye and development of signs of a kseroz are characteristic. A syndrome of a dry eye occurs at 9-18% of the population, is more often at women (nearly 70% of cases), disease frequency considerably increases with age: up to 50 years - 12%, after 50 – 67%.
Normal the forward surface of an eyeball is covered continuous thin (about 10 microns) with the plaintive film having three-layer structure. The external lipidic layer – an oily secret of meybomiyevy glands provides sliding of an upper eyelid on the surface of an eyeball and slows down evaporation of a plaintive film. The water layer with the dissolved electrolytes and organic compounds washes away foreign matters from an eye, provides a cornea with nutrients and oxygen, creates immune protection. The Mutsinovy layer – a mucous secret of scyphoid and epitelialny cages directly contacts to a cornea: does its surface equal and smooth, connecting with it a plaintive film and providing high quality of sight.
Approximately each 10 seconds the plaintive film is broken off, initiating the blink movement a century and updating of the plaintive liquid restoring its integrity. Violation of stability of a prerogovichny plaintive film leads to its frequent ruptures, dryness of a surface of a cornea and a conjunctiva, development of a syndrome of a dry eye.
Reasons of a syndrome of a dry eye
Leads insufficient amount and quality of plaintive liquid, and also the excessive evaporation of a prekornealny plaintive film reducing time of its safety or volume to a syndrome of a dry eye.
The internal diseases and syndromes connected with decrease in a slezoproduktion can be the reasons of development of a syndrome of a dry eye: autoimmune (Shegren's syndrome), diseases of haemo poetic and reticuloendothelial systems (Felti's syndrome, malignant lymphoma), endocrine dysfunction (endocrine ophthalmopathy, climax), pathology of kidneys, exhaustion of an organism and infectious diseases, skin diseases (puzyrchatka), pregnancy.
Pathology of organs of vision (chronic conjunctivitis, hems of a cornea and a conjunctiva, neuroparalytic keratit, , dysfunction of plaintive gland) and the expeditious ophthalmologic interventions destabilizing a plaintive film (a forward radial keratotomy, a cornea fotoablyation, a keratoplasty, plasticity of a conjunctiva, correction of a ptoz) can lead to a syndrome of a dry eye.
There are artefitsialny factors causing violation of stability of a plaintive film - dry air from conditioners and fan heaters, hard work with the personal computer, viewing of the TV, an error of selection and use of contact lenses, ecological trouble.
Reduces a slezoproduktion and prolonged use of the eye medicines containing beta , holinolitik, anesthetics causes a syndrome of a dry eye; some system medicines (hormonal contraceptives, antihistaminic, hypotensive).
Emergence of a syndrome of a dry eye is promoted by too rare blink movements, avitaminosis with violation of exchange of fat-soluble vitamins, genetic predisposition, age after 40 years, belonging to a female. Reduction of frequency of blink movements can be caused by decrease in sensitivity of a cornea of functional or organic character.
Classification of a syndrome of a dry eye
According to domestic classification, on pathogenesis allocate the syndrome of a dry eye which developed owing to decrease in volume of secretion of plaintive liquid, the increased evaporation of a plaintive film, and also their combined influence; on an etiology distinguish a sindromalny dry eye, symptomatic, artefitsialny.
The syndrome of a dry eye can be expressed by various clinical forms: recidivous macro - and microerosion of a cornea or conjunctiva of an eyeball; dry keratokonjyunktivit, nitchaty keratit.
On severity distinguish easy, average weight, heavy and especially severe form of a syndrome of a dry eye.
Symptoms of a syndrome of a dry eye
Clinical manifestations of a syndrome of a dry eye are very various and in many respects are defined by disease severity. Reddening, burning and gripes in eyes belong to subjective symptoms of a syndrome of a dry eye feeling of a foreign matter (sand) in a conjunctival cavity; dacryagogue, hypersensibility to light, bystry fatigue; indistinct sight, pain at instillation of eye drops.
Symptoms of a syndrome of a dry eye are usually more expressed in the evening, and also at stay in the dry or polluted room, on cold, wind, after long or hard visual work.
Objective signs of a syndrome of a dry eye are xerotic changes of a cornea and conjunctiva of various degree of expressiveness (corneal and conjunctival ). At an easy current of a corneal and conjunctival kseroz compensatory increase in a slezoproduktion (giperlakrimiya) and increase in height of the lower plaintive meniscus develops. At a medium-weight kseroz reflex dacryagogue decreases, decrease or completely there are no plaintive meniscuses, there is a feeling of "dryness" in eyes, napolzany the swelled conjunctiva on free edge of a lower eyelid and its shift together with the stuck century at the blink movements. Heavy corneal and conjunctival it is shown by the following clinical forms: the nitchaty keratit, a dry keratokonjyunktivit and a recurrent erosion of a cornea proceeding against the background of the available manifestations of a syndrome of a dry eye.
At a nitchaty keratit on a cornea multiple epitelialny growths, manifestations of moderately expressed corneal syndrome without inflammatory changes of a conjunctiva are observed.
At a dry keratokonjyunktivit the expressed corneal and conjunctival changes of inflammatory and degenerate character are noted: subepitelialny turbidity, dimness and a roughness of a cornea, saucer-shaped epitelizirovanny or neepitelizirovanny deepenings on its surface, sluggish hyperaemia, hypostasis and loss of gloss of a conjunctiva of an eye, more expressed adhesion of an eyeball with a conjunctiva a century.
At a recurrent erosion of a cornea periodically there are superficial microdefects of its epithelium which remain to 3-5 and more than a day, after their epitelization the long discomfort is noted.
Especially heavy corneal and conjunctival usually develops at a full or partial nesmykaniye of an eye crack. The syndrome of a dry eye against the background of the expressed lack of vitamin A is shown by a scaly metaplaziya of an epithelium and a keratinizatsiy conjunctiva.
The syndrome of a dry eye is often combined with blefarity. The syndrome of a dry eye can lead to heavy and irreversible xerotic changes and even, perforation of a cornea.
Diagnostics of a syndrome of a dry eye
Diagnostic inspection of the patient at a syndrome of a dry eye begins with collecting complaints, assessment of the anamnesis and clinical symptoms of a disease, for the purpose of identification patognomonichny and indirect signs of a corneal and conjunctival kseroz.
At fizikalny inspection concerning a syndrome of a dry eye external examination during which the ophthalmologist defines a condition of skin a century, sufficiency of their smykaniye, character and frequency of blink movements is performed. At biomicroscopy of an eye the condition of a plaintive film, a cornea, a conjunctiva of an eyeball and a century, height of plaintive meniscuses is analyzed.
At suspicion on a syndrome of a dry eye carry out flyuorestseinovy instillyatsionny test with use of the painting solution allowing to define time of a rupture of a plaintive film and to reveal existence of the dry centers - the sites of a cornea deprived of an epithelium. By means of special tests investigate the speed of formation of plaintive liquid - a total slezoproduktion (Shirmer's test), quality and speed of evaporation of a plaintive film (Norn's test). Noninvasive assessment of durability of a prerogovichny plaintive film is carried out by means of a tiaskopiya (survey in the polarized light) also by measurements of thickness of a lipidic layer.
Full ophthalmologic inspection at a syndrome of a dry eye also includes a laboratory research of osmolarity and a crystallography of plaintive liquid, a cytologic research of dab from a conjunctiva (including impression). At system or endocrine diseases in the anamnesis of the patient with a syndrome of a dry eye conduct the corresponding immunological and endocrinological researches.
Treatment of a syndrome of a dry eye
Treatment of a syndrome of a dry eye is focused on elimination of etiologichesky factors of a kseroz; full moistening of an eye surface and increase in stability of a prerogovichny plaintive film; knocking over of pathological changes of a cornea and conjunctiva and prevention of complications.
Most widely at a syndrome of a dry eye apply regular instillations of the medicines of an artificial tear (a tear natural, gels with karbomery and dekspantenoly) allowing to restore rather stable plaintive film on the surface of an eyeball. At an easy current of a syndrome of a dry eye appoint medicines of low viscosity, at medium-weight and severe forms – average and high viscosity (gels), in especially hard cases of a kseroz – medicines of low viscosity without preservatives.
Also at a syndrome of a dry eye instillations of anti-inflammatory and immunotropny means, in the presence of degenerate xerotic changes of a cornea – metabolic medicines are shown. In addition appoint antihistamines, stabilizers of membranes of corpulent cages, stabilizers of lizosomalny membranes of macrophages.
Surgical treatment of a syndrome of a dry eye is carried out if necessary to limit outflow and evaporation of a native or artificial tear from a conjunctival cavity, to increase inflow of plaintive liquid, to eliminate the arisen complications (a xerotic ulcer, perforation of a cornea). Closing of slezootvodyashchy ways of an eye is carried out by the following methods: an obturation of plaintive points by means of special pro-barrels; plasticity of plaintive points conjunctiva or skin; diatermokoagulyation, lazerkoagulyation or surgical mending.
Obturation of a plaintive tubule tiny silicone traffic jams and a conjunctival covering of a plaintive point at a syndrome of a dry eye are more preferable as are low-invasive, more effective and do not cause irreversible changes.
At the expressed cornea kseroz (a xerotic ulcer, a keratomalyation) and lack of effect of medicamentous therapy and an obturation of slezootvodyashchy ways, at a syndrome of a dry eye make a keratoplasty. To patients with an incomplete smykaniye a century, the wide eye crack and a rare blinking showed a lateral tarzorafiya.
Innovative ways of treatment of a syndrome of a dry eye is transplantation of salivary glands from an oral cavity in a conjunctival cavity, implantation of dakriorezervuar in soft tissues of the patient with removal of special tubes in a conjunctiva cavity.
Forecast and prevention of a syndrome of a dry eye
Even at an easy current the syndrome of a dry eye demands performing full and adequate treatment in order to avoid development of a serious illness of a conjunctiva and a cornea with possible loss of sight.
It is possible to warn a syndrome of a dry eye, having reduced impact on eyes of artifitsialny factors, carrying out preventive treatment of internal diseases, including pathologies of organs of vision, using enough liquid, rationally eating, making the blink movements at visual loading more often.