Congenital cataract – the partial or full cataract of an eye developing vnutriutrobno. In different degree it is shown from the moment of the child's birth: from hardly noticeable whitish spot to completely struck crystalline lens. The congenital cataract is characterized by decrease in sight or its full loss, also at children squint and is noted. Primary diagnostics is carried out prenatalno, after the birth the diagnosis is confirmed by an oftalmoskopiya and slot-hole biomicroscopy. Surgical treatment is shown; the lensvitrektomiya is carried out in the first months of life at uncomplicated cases.
Congenital cataract – the pathology of an organ of vision which is often found in clinic of many children's diseases. In 36% of cases results from the postponed pre-natal infections. The general frequency of a congenital cataract in population – 1-9 cases on 10000 newborns. A share of the given disease among all defects of an organ of vision – 60%. Gender distinctions in incidence are not revealed, except for genetic mutations which are more often shown at boys while girls often remain carriers of the changed gene asymptomatically. Now special attention is paid to a problem of a congenital cataract in pediatrics. The disease is caused by a set of the reasons therefore efforts of doctors are directed to prevention and early diagnosis of a cataract. Methods of surgical treatment are improved. All measures are directed to preservation of sight of the child for the best social adaptation.
Reasons of a congenital cataract
Most often the congenital cataract accompanies the TORCH infections group into which the rubella, toxoplasmosis, a virus of herpes and a Cytomegaloviral infection enter. At the same time it is not the only symptom. The special signs are characteristic of each disease. The reason of a congenital cataract, the second for frequency, – exchange violations at the child: galactosemia, Wilson's disease, gipokaltsiyemiya, diabetes and others. Occasionally the disease meets in connection with genetic mutations on autosomno-prepotent and autosomno-recessive to type. The mutations linked to the X-chromosome are noted even less often.
In case of chromosomal pathologies (a Down syndrome, a syndrome of cat's shout, a dot hondrodisplaziya, a syndrome of Hallermana-Shtrayfa-François, etc.) the congenital cataract is also not the only symptom. As a rule, it is accompanied by the violations of physical and intellectual development and other manifestations specific to a concrete nosology. It is exogenous the influencing causes of illness antibiotic treatment of the pregnant woman, therapy as steroid hormones, radiation therapy and influence of other teratogenny factors can serve. Separately allocate a congenital cataract of premature.
The cataract occurs on one of two mechanisms. First, initially wrong laying of an organ of vision. It is characteristic of pre-natal infections at early stages of pregnancy, chromosomal pathologies and in general any teratogenny influence if it takes place in the first weeks of pregnancy when at a fruit the system of organs of vision is formed. The second mechanism is a defeat of already created crystalline lens. Often occurs at exchange violations (a galactosemia, diabetes, etc.), influence of the external damaging factors during pregnancy (the second or third trimester). Anyway the crystalline lens protein structure because of what it ovodnyatsya gradually changes and then loses the transparency owing to what the congenital cataract develops.
Classification of a congenital cataract
The disease is divided into types depending on an arrangement of a zone of turbidity and its extensiveness. Allocate the following types of a cataract: kapsulyarny, polar (forward and back), layered (filmy), nuclear, full.
The Kapsulyarny congenital cataract is a decrease in transparency of the forward or back capsule of a crystalline lens. The crystalline lens at the same time is not mentioned. Violation of sight is more often slightly, however also the blindness meets if damage of the capsule is extensive, or are struck both the forward, and back capsule at the same time.
At a polar cataract of change mention a forward or back surface of a crystalline lens. The capsule is most often also involved in process. Bilateral defeat is characteristic of this look. Extent of violation of sight strongly varies.
The layered cataract is a turbidity of one or several central layers of a crystalline lens. The most widespread option of a congenital cataract, as a rule, defeat bilateral. Sight is usually reduced considerably.
Nuclear cataract call turbidity of the central part of a crystalline lens – its kernel. Such version meets at all hereditary causes of illness. Defeat is bilateral, sight decreases up to a total blindness.
The full congenital cataract is characterized by turbidity of all crystalline lens. Extent of turbidity varies, but more often such form of a disease completely deprives of the child of sight. Defeat is bilateral.
By origin the congenital cataract shares on hereditary and pre-natal. The first of them is given to the child from one of parents, the second develops at a fruit directly during pregnancy. Atypical (polymorphic) consider a cataract of irregular shape. Allocate a unilateral and bilateral cataract, also the disease is classified by extent of decrease in sight (allocate the I-III degrees). Some classifications separately designate the complicated cataract form, however it is so possible to call any cataract which is followed by diseases of other bodies.
Symptoms of a congenital cataract
The main symptom – a cataract of this or that degree. In a clinical picture it can be shown by a noticeable white spot against the background of an iris, however more often there are cases of a congenital cataract when this sign is absent. At unilateral defeat squint, as a rule, meeting is noted. Sometimes instead of it find pathological rhythmic trembling of an eyeball. Almost at all children with a bilateral congenital cataract it is noted . Approximately at two-month age healthy children can already look after a subject, but at a disease of it does not occur, or the kid turns towards a subject only a healthy eye all the time.
Diagnosis of a congenital cataract
Primary diagnostics is carried out to time of planned ultrasonography screening of pregnant women. Already in the second trimester the crystalline lens is visualized on ultrasonography by a dark stain (normal). There are cases when on the second ultrasonography it is not possible to exclude or confirm authentically the diagnosis yet, and then it can be made in the third trimester. It is important to understand that at this stage the diagnosis cannot be confirmed for 100%, but the disease can be suspected, and the statistics shows that the method is highly reliable.
After the child's birth the pediatrician will be able to notice only an intensive cataract of the central localization. Most often it is not possible to diagnose a cataract at fizikalny survey. Survey of the children's ophthalmologist is obligatory for all newborns. The expert will be able to suspect and confirm the diagnosis of a congenital cataract, having noticed even insignificant violation of passability of light through a crystalline lens. Also the doctor will find squint and . As the congenital cataract accompanies many pre-natal infections, exchange to violations, chromosomal pathologies, at diagnosis of these diseases the child will be examined for an exception of eye defects.
For diagnosis of a congenital cataract the following tool methods are used: oftalmoskopiya, slot-hole biomicroscopy, ultrasonography of an eyeball. All of them allow to verify change of transparency of a crystalline lens and to exclude diseases, similar in clinic. In particular, retinopathies at children are also characterized by deterioration in sight and squint, however in this case damage of a retina of an eye is the reason, and survey by means of the ophtalmoscope will allow to establish it. Sight, as well as a congenital cataract can significantly reduce tumors of external department of an eye. Visual survey, an oftalmoskopiya, the ultrasonography methods and X-ray diagnostics helps to differentiate them.
Treatment of a congenital cataract
Conservative methods of treatment are justified only at an insignificant cataract. In therapy cytoprotectors and vitamins are used. However most often the congenital cataract is treated quickly. Surgical removal needs to be carried out as soon as possible to provide conditions for the correct development of eyes. Cataract surgery – a lensvitrektomiya – is considered the least injury-causing at children's age therefore it is carried out most often. The state after removal of a crystalline lens is called an afakiya and demands long dynamic observation and correction of sight.
Afakiya korrigirutsya by means of points or contact or intraocular lenses. Observation at the ophthalmologist is necessary for the purpose of an exception of possible postoperative complications, in particular, of glaucoma. Several decades ago the list of complications was more extensive, but with introduction of a lensvitrektomiya their main part managed to be minimized. So, cases of an otsloyka of a retina, hypostasis of a cornea, an endoftalmit and an ambliopiya extremely seldom meet.
Forecast and prevention of a congenital cataract
Modern methods of surgical treatment provide the favorable forecast in most cases. Removal of the struck crystalline lens aged before half a year (it is better in the first weeks and months) and further correction of sight promote good social adaptation of children in adulthood. It should be noted that the monocular congenital cataract will respond to treatment much worse and till present gives the greatest number of all complications connected with this disease. Besides, the cataract extremely seldom meets separately therefore the forecast is defined as well by associated diseases: infections, exchange violations, chromosomal pathologies etc.
Prevention of a congenital cataract is carried out to pregnancy time. It is necessary to exclude contact of the woman with infectious patients, to minimize influence of teratogenny factors (alcohol, smoking, beam methods of diagnostics and therapy, etc.). Observation of the endocrinologist throughout all pregnancy is shown to the women having diabetes. Chromosomal pathologies are in most cases diagnosed before childbirth, and further the woman can already make the decision on termination of pregnancy or conscious incubation of the child. Specific prevention of a congenital cataract is absent.