Cataract - the ophthalmologic disease connected with a clouding of the eyens lens and causing various degrees of a visual disturbance
Types of a cataract
All cataracts are subdivided into two main groups: congenital cataracts and the acquired cataracts. The variety of clinical forms is characteristic of congenital cataracts that depends on a look, localization and degree of a cataract. Congenital cataracts in most cases do not progress, limited, with characteristic localization of pomutneniye. The acquired cataracts almost all treat progressing.
On the cause (etiology) the acquired cataracts are divided into several groups:
- age (senile, senile) cataracts;
- the traumatic cataracts (which arose as as a result of a stupid injury (contusion), and the getting eyeball wound);
- the complicated cataracts (at inflammation of a choroid of an eye (uveitis), short-sightedness of high degree, glaucoma, a pigmentary degeneration of a retina and some other diseases of an eye);
- the beam cataracts (connected with damage of a crystalline lens by a radiant energy) – infrared beams (usually professional cataracts – for example, a cataract of glass blowers), x-ray, radiation;
- toxic cataracts (the large number of the "medicinal" cataracts which are formed as result of side effect at long reception of a number of medicines also belongs to this group: corticosteroids, anti-malarial drugs, Amiodaronum, etc.);
- the cataracts caused by the general diseases of an organism (diabetes, a hypothyroidism, metabolism diseases).
On maturity degrees, an age cataract divide into four stages:
- initial cataract;
- unripe cataract;
- mature cataract;
- overripe cataract.
- Decrease in visual acuity
- Emergence or strengthening of short-sightedness
- The ability to read and write without plus points inexplicably returns to some time, but at all this objects are visible indistinctly, with indistinct contours
- Doubling of the image
- The pupil which traditionally looks black can get a grayish or yellowish shade
- At the bulking-up cataract the pupil becomes white
- People with a cataract can complain of the raised or reduced svetovospriimchivost, say that the world in limits became some dim
- Intolerance of bright light, the best sight in cloudy weather or in twilight. This symptom is characteristic of pomutneniye in the central area of a crystalline lens
- Increase in a problem with sight at night or in the conditions of low illumination
- Light sensitivity, patches of light, auras within light sources
- It seems that colors are lost, objects can seem turned yellow
- The difficulties arising when performing everyone deny activity because of sight problems
- The congenital cataract at the kid can be shown by squint, presence of a white pupil, decrease in sight that is found after lack of reaction to silent toys
- Research of peripheral blood on the content of glucose and calcium
- Biochemical analysis of blood with definition of the Russian Federation, ANAT and other indicators in the presence of a characteristic clinical picture
- Active tuberculosis detection.
- Quality standard of visual acuity and refraction; in case of the significant decrease in visual acuity, tests for definition of localization in space of a source of bright light are shown. The possible hyperglycemia at SD can cause osmotic changes in substance of a crystalline lens and affect results of researches
- Determination of retinal visual acuity (the isolated ability of a retina to perceive visual objects, at the same time a condition of the refracting environments of an eye is not considered; definition is made by means of the directed bunch of laser radiation). The similar research is often conducted in the preoperative period for the purpose of exact forecasting of postoperative visual acuity
- The retina angiography with flyuorestseiny is shown for detection of the accompanying pathology at discrepancy of visual acuity of degree of a cataract.
- Other reasons of decrease in visual acuity — superficial turbidity of a cornea owing to cicatricial changes, tumors (including the retinoblastoma demanding immediate surgical treatment because of high risk of metastasis), amotio of a retina, retina hems, glaucoma. Biomicroscopic or oftalmoskopichesky examination is shown
- The disorder of vision at elderly often arises in interaction of several factors, for example a cataract and a macular degeneration therefore at establishment of the reason of decrease in visual acuity it is not necessary to be limited to detection of only one pathology.
Causes of a cataract
Treat the factors contributing to the development of a cataract:
- genetic predisposition;
- eye injuries (chemical, mechanical, contusional injuries);
- various eye diseases (including glaucoma, short-sightedness of high degrees);
- endocrine disorders (disbolism, diabetes, avitaminosis);
- beam, microwave oven and ultra-violet radiation;
- long reception of a number of medicines;
- the raised radiation;
- adverse ecological situation;
- toxic poisoning (naphthalene, dinitrophenol, thallium, mercury, ergot);
Treatment of a cataract
In an initial stage of a cataract when sight not lower than 0.1, i.e. the patient still can count fingers of the doctor from distance not closer than 5 m, apply medicamentous methods of treatment. Use medicines in the form of drops, eye baths, by a fonoforez and an electrophoresis.
Medicines contain the substances improving food of a crystalline lens and in this regard supporting its transparent structure. The main direction of such treatment is normalization of metabolism and oxidation-reduction balance in a crystalline lens. However it is not possible to achieve full normalization of exchange processes yet what results of a primeniye more than 60 medicines offered now by pharmaceutical firms testify to.
Only the ophthalmologist who will define the drug corresponding to a type of a cataract can appoint the correct treatment. To the address to the ophthalmologist sick it is possible to take inside vitamins and the polyvitaminic drugs (Undevitum, Panhexavitum, etc.).
In a considerable cataract the surgical treatment is shown. Extraction of a cataract is carried out under a microscope by two methods — intrakapsulyarno and ekstrakapsulyarno (removal of a crystalline lens with the capsule and without it). Each method has the merits and demerits. Leaving in an eye of the capsule of a crystalline lens keeps normal anatomic relationship of structures of an eye, however its turbidity — a secondary cataract is possible. Removal of a crystalline lens with the capsule excludes formation of a secondary cataract, but promotes a vitreous exit in an anterior chamber. Such complication is called a vitreous-tug sundome.
Recently microsurgical removal of a kernel and lenticular masses with leaving of the back capsule of a crystalline lens gains ground (for example, laser treatment of a secondary cataract which is rather safe manipulation).
After removal of a crystalline lens of eyes owing to loss of a big positive lens it turns out gipermetropichesky (far-sighted) therefore he sees badly. In this case its correction is necessary. For this purpose often apply points in the form of collective lenses +10... + 12 dioptries. If the patient had a short-sightedness, then correction is required smaller, and in far-sightedness — big.
In recent years the aphakia (absence in a crystalline lens eye) is korrigirut a contact lens or make replacement of a muddy crystalline lens by artificial — an intraocular lens (IOL). It is installed in an anterior chamber of an eye (perednekamerny fastening of IOL), or in the back camera (zadnekamerny fastening of IOL), or directly in the capsule of a remote crystalline lens that is considered the most perspective method of fastening of IOL. Each of types of correction of an aphakia has the merits and demerits. Indications for the sake of appearances corrections of an aphakia are defined by the ophthalmologist making operation.
Prevention of a cataract
In most cases the cataract develops owing to aging. Regular ophthalmologic surveys are the most effective method of detection of a cataract at an early stage. To patients 65 years are more senior annual inspection is recommended. For prevention of a cataract it is recommended to leave off smoking. Smoking increases number of free radicals, the last contribute to the development of a cataract. It is necessary to adhere to the balanced diet, some doctors believe that consumption of vegetables and fruit has some preventive effect concerning a cataract. Protect eyes from sunlight, use sunglasses on the street. Researchers continue to develop new ways of prevention of a cataract, for example, drugs which will replace surgical treatment of a cataract. However for today surgical treatment is the best way of treatment of a cataract in the absence of other diseases.