Visual acuity and field of vision changes at expressed the pomutneniyakh in a crystalline lens kernel

Depending on primary localization of pomutneniye in a crystalline lens, the clinical picture of a cataract can have some features.

At a nuclear cataract visual acuity afar originally suffers, subjects seem as in fog. In the afternoon, at a bright sunlight, the pupil is narrowed also amount of light getting through muddy central departments of a crystalline lens, becomes insufficient. On the contrary, in evening and twilight time, as a result of increase in the sizes of a pupil and, therefore, amount of light passable through remained still transparent sites of a crystalline lens, brightness of the visible image amplifies. Such patients see in twilight light much better.

At localization of pomutneniye in bark (a kortikalny cataract) at initial stages of process visual acuity practically doesn't suffer. Such cataracts are characterized by slower progressing.

The back subkapsulyarny cataract is quite often shown by a fast-progressing current and accompanied by loss of subject sight within several months.

Diagnostics

In the presence of the expressed pomutneniye in a crystalline lens, very difficult, and at times it is simply impossible to conduct research of a condition of a vitreous body and a retina standard methods of ophthalmologic inspection. In this regard it is required carrying out a number of additional, specialized methods of research.

Thus, all process of inspection of the patient with a cataract can be divided into the following methods of research:

• Standard (routine) methods of ophthalmologic inspection;

• Determination of visual acuity (vizometriya);

• Research of fields of vision (perimetry);

• Measurement of intraocular pressure (tonometriya);

• Research of a forward piece of an eye (biomicroscopy);

• Survey of an eye bottom (oftalmoskopiya);

• Research entopicheskikh of phenomena;

Additional (special) methods of the research, which performance is obligatory for each patient:

• Refractometry;

• Ophthalmometry;

• Definition of the front and back axis (FBA) of an eyeball (ultrasonography scanning in the A-mode);

• Electrophysiological methods of research (threshold of electric sensitivity, lability of an optic nerve, critical frequency of merge of flashings);

• The additional (special) methods of research which are carried out on indications;

• Ultrasonography in the V-mode;

• Ultrasonic biomicroscopy;

• Densitometry;

• Endotelialny biomicroscopy;

• Laboratory methods of research (within preparation for hospitalization).

The first group included methods of standard ophthalmologic inspection. The special attention is paid to biomicroscopy – eyeball researches by means of the special device – a slot-hole lamp. The slot-hole lamp – some kind of microscope also is one of the main tools of the ophthalmologist. This device allows to receive an optical cut of a crystalline lens, in details and under big increase to investigate its structure, to define primary localization and extent of pomutneniye, to estimate a dislocation (shift) of a crystalline lens.

Research the entopicheskikh of phenomena (for example, mechanophosphene, an autooftalmoskopiya phenomenon, etc.) is of great importance. These simple methods allow to judge allegedly safety of the neuroreceptor device of a retina at expressed the pomutneniyakh in the crystalline lens, excluding possibility of survey of an eye bottom.

The second group included the methods necessary for calculation of force of an artificial crystalline lens (an intraocular lens, IOL). There are special formulas for calculation of force of IOL, as basic data in which it is necessary to enter ophthalmometry indicators (the research, allowing to determine refracting force of a cornea) and PZO.

The third group – the methods, appointed oftalmokhirurgy according to the indications, necessary for a choice of this or that equipment of operation, the IOL type, etc. in the V-mode is applied by ultrasonography, generally at expressed the pomutneniyakh in a crystalline lens and a vitreous body for diagnostics and localization of structural changes in an eye cavity, and also determination of their character and prevalence.

Laboratory methods of research are appointed, as a rule, before hospitalization. They include the general analysis of blood and urine, the biochemical analysis of blood, a blood test on HIV, syphilis, hepatitises B and C, the roentgenogram of bodies of a thorax and additional bosoms of a nose. Besides, the conclusions of the therapist, the stomatologist, the ENT specialist, according to indications – other experts (the endocrinologist, the nephrologist, etc.) are necessary. All this becomes for the purpose of identification of contraindications to operation (a decompensation of the general diseases, identification and sanitation of the centers of a chronic infection) which can complicate a current of the postoperative period.