Apr 19, 2010

Investigation of optical media in the eyes of the transmitted light

Inspection carried out to determine, primarily, transparency of the lens and vitreous. This desk lamp also need to install the left of the patient, but behind his head. The light from her doctor with ophthalmoscope take to send a pupil of the eye, seeking to glow red. This occurs when you capture the rays reflected from the choroid (the light reflex from the fundus). If the path of light rays will be fixed or floating cloud, then on a red glow, they will look dark structures of any shape. Location can be defined by the parallax, ie direction and amplitude of the displacement estimated shadow on a stable point, such as the center of the pupil. For this purpose it is necessary that the eye has made two movements - up and down or left and right. Then it turns out that cloud lying anterior to the plane of the pupil, are moving in the same direction as the eye. Opacity is located in this plane are displaced under the same conditions in the opposite direction.

When diffuse vitreous opacities with fundus reflex is attenuated more strongly, the closer these opacities.

Characteristics of the basic concepts

Exophthalmos - vystoyanie eyeball from the orbit at any distance greater than the limit value of the normal rate (18 mm).

Enophthalmos - acquisition of the eyeball in the orbit for any amount exceeding the limit value of the normal rate (13 mm).

Methods

The measurement can be performed with a special tool - proptometer or conventional millimeter ruler. In the latter case it is performed as follows. Line puts on the outer edge of the orbit of the patient, whose head is turned in profile, and determine what its division is at the top of the cornea. Normally vystoyanie eyeball varies from 13-18 mm, and the asymmetry in the position of fellow eyes did not exceed 1 mm.

Possible and only indicative version measuring exophthalmos, when the doctor is behind the seated patient and the index finger of the right and left hand raises his upper eyelids. We estimate (when you look down the test) the degree vystoyaniya tops of the corneas of both eyes in relation to the line, as if joining the nail phalanx of index fingers of the doctor
Investigation of the severity of central vision (vizometriya)

Determination of the visual possibilities in early childhood (from birth to 3-4 years)

The severity of central vision is a function that, like other visual functions, develops in the child gradually, with growth and development of his eyes and brain. On the visual possibilities of the newborn can be judged by the presence or absence of his motor reflexes to a visual stimulus. These include the following:

protective closing eyelids and upward deviation of the eyes.
the same thing with throwing the baby's head back (reflex Paper).
pupillary constriction (estimated direct and friendly reaction).
reflexive turn the baby's head and eyes to the source of light.
tracking eye moves slowly over the source of light.
Child 2-3 weeks of life can already show bright objects. If they get into his field of vision and perceived, then make eye tracking movements.

Baby 1-2 months, if view, which can not yet metrirovat, can have long-term fix with both eyes moving object (a bright toy).

Baby 2-5 months may already have the elements shaped view. In order to verify its presence is useful to use a bright red ball with a diameter of 4 cm he was hung on a thread, well lit and slightly shaking, show the child, noting the distance from which he begins to follow him.

A child 6-12 months and older by the method described above to show the ball is much smaller - 0.7 cm in diameter If, however, it turns out that he could not see, the study should continue with the object size. By the way, to quickly determine the outcome vizometrii advisable to use the table below ES Avetisova et al. (1987).

Determination of visual acuity in children aged 3-4 years and older and adults

Visual acuity - an indicator whose value is determined by the ability of the eye to the separate perception of the two light points at the smallest angle. The latter is formed by two rays emanating from the extreme points fixed by the object and intersecting at its nodal point. For convenience in the value of visual acuity expressed still not in the corner, but in relative terms with the help of special tables, first proposed Snellenom (Snellen G., 1862). They adopted as a physiological angle, equal to 1 '. This rule has remained common, and therefore all subsequent vizometricheskie table built so that each of the test sign visible from a fixed distance from the perspective of the 5 'and its distinctive details - in 1'. In accordance with the proposal of the same magnitude of Snellen visual acuity in many countries around the world expressed measure as a fraction: the numerator indicates the distance from which the study was carried out, - d (standard Snellen is 20 feet, that is 6 meters), and denominator - the distance from which a number of signs reading tables are visible in the norm at a given angle of view - D.

The study is fixed as follows:

Vis OD (OS) = 20/20 or 20/50, etc. Our country uses the metric table type Monuaye designed to show from 5 meters. They allow you to determine the visual acuity of the so-called decimal system - from 0,1 to 2,0. For the corresponding calculations used as already mentioned formula Snellen:

Vis = d / D.

Vizometriyu should be performed in 2 versions - to give (5 m) and near (33 cm), and separately for each eye. It is also useful to know and value of binocular visual acuity, because, as a rule, it is higher than monocular (≈ in 0,1-0,2).

In our country, the study of visual acuity to produce a given in the tables Sivceva (letters and Landolt rings) and Orlova (with children's pictures), placed in the apparatus Roth, a distance of 5 m. They should cover the filament in 40 Tues The lower edge of the table should be at eye level, sitting on a chair patient. Standards set for adults is 120 cm for the children she did not declare, but it is clear that in this case the apparatus Roth spreadsheet should hang lower (30-40 cm). Given the large age range of children who can vizometriya, preferably in the eye room to have two devices Roth and install them at various levels (eg, distance to the lower edge of the floor level at 80 and 100 cm).

Order vizometricheskogo study is as follows. First, determine the acuity of the right eye, then - the left. Neissleduemy eyes have an opaque cover flap. It is impossible to squint or tightly closed hand. Only the full visual acuity. The first six rows (Vis = 0,1-0,6) are read, if they learn all the signs. In the 7-10th rows (Vis = 0,7-1,0) allowable error in one sign.

For visual acuity less than 0.1 investigated to move toward the table until the moment when he sees one of her line. Subsequent vizometrichesky calculation based on a formula Snell (see above). The research process can be simplified if the doctor will show the patient with different distances fingers of his hand (corner of their value approximately corresponds to the details of tests from the first row table Sivceva). With this method of measuring 1 meter distance is equivalent to visual acuity of 0,02. Hence, for example, that if properly run your fingers on 1,5 m visual acuity equal to 0,03, at 2 m - 0,04, 2,5 m - 0,05, 3,5 m - 0,07 etc.

Determination of visual acuity for near vision is produced by a different (small) tables Sivceva. It is designed to show from 33 cm and strengthened in a special box with a handle. The test should take it in hand and holding at a given distance, to find and read separately by each eye, the text that he is free to regard it. The values of visual acuity in the table of this type are listed at the beginning of each text block. Abroad, now widely distributed small-format multi-purpose tables, which in addition to vizometrii (from a distance of 40 cm) make it possible to determine the patient position the nearest point of clear vision of each eye and the size of their pupils.

Evaluation of the functional state of the central sections of the retina in patients with clouding of optical media

Light banded sample Primrose (Primrose J., 1956)
Before investigational eye set cylinder axis Maddox, for example, horizontally. Healthy eye shield. Then use the ophthalmoscope through the said cylinder in the eye direct light beam. When a positive test subject sees a vertical light strip. The correctness of his answers can be easily controlled by changing the position of the axis of the cylinder. The test is easily perceived by children and adults.

Positive test Primrose suggests that successful treatment of patients may have visual acuity of at least 0,03 (Sosnowski VV, 1990).

Autooftalmoskopiya
The study is carried out in a darkened room. The patient is asked to close his eyes, and then to the upper eyelid interested eyes tip transillumination (light intensity from 60 to 110 cd/m2). Shifting the tip of the left and right 0,5 cm, the patient is asked to describe what he had with the saw. Normally in such a lit him a picture of "retinal vascular tree." Next tip transillumination to set a lower eyelid and to the corners of the palpebral fissure of the same eye. The result of the study is considered positive (is marked «+»), when analyzed vidit picture of the vascular "tree" when lit eyeballs with all the above points. The presence of defects in it being marked "-", which shall be placed in the appropriate box of the protocol form. The nature of the defect of the vascular "tree" is described verbally.

According VV Sosnowski (1990), a positive result autooftalmoskopii (EPA) indicates that the successful treatment of patients may have visual acuity of at least 0,2.

Antiallergenic tools

This group of drugs include antioxidants and protivokataraktalnye drugs (monocomponent and combination).

Deterrent cataract development

Kvinaks

The active ingredient of the drug (digidroazapentatsin polisulfonat sodium) has an affinity with the SH-groups of soluble proteins of the lens and because of this fact protects them from the degenerative effects of the so-called kvinoidnoy substance. The latter is a product of disturbed metabolism of amino acids such as tryptophan and tyrosine. Medications are used for cataracts of any etiology. Producing kvinaks in bottles of 15 ml. Manufacturer - company Alcon.

Oftan Katahrom

The positive effect of the drug based on the oxidizing action of cytochrome C and enrichment of the basis of eye tissues with oxygen. You can apply for cataracts of any etiology. Contraindications - intolerance of cytochrome C produced the drug in vials of 10 ml. Manufacturer - Company Santen.

Vita Yodurol

The drug contains 5 groups of active principles: adenosine triphosphate (ATP), glutathione or cysteine, vitamin B1, nicotinic acid and iodine compounds. Producing it in bottles of 10 ml. Apply with cataracts of any etiology. Manufacturer - firm Ciba Vision Ophthalmics.

Vitafakol

Active ingredients - cytochrome C and sodium succinate, which are activators of metabolism and respiration cells, as well as adenosine (stimulates the synthesis of cyclic AMP), nicotinamide (stimulates the synthesis of NAD) dehydrogenases and cofactor (vitamin B2). Together, these components improve the energy level of the lens. Contraindications - the development of allergic conjunctivitis (reaction to cytochrome C). Use in patients with cataracts of any etiology. Producing it in bottles of 10 ml. Manufacturer - firm Ciba Vision Ophthalmics.

Stimulants regeneration

Vitasik

Active substances - adenosine, thymidine, cytidine, uridine and 5-disodium-guanozinmo-nofosfat. The combination of these 5 nucleotides attached dropwise properties, allowing their use for the treatment of patients with impaired integrity of the corneal epithelium. The drug has also protivokataraktalnymi properties. Produced the drug in vials of 10 ml. Manufacturer - firm Ciba Vision Ophthalmics.

Taufon

Active Home - taurine. Mode of action - restorative and antikataraktalnoe. Helps normalize the function of cell membranes, activation of metabolic and energy processes, the preservation of electrolyte composition of the cytoplasm of the cell (due to accumulation of potassium ions and calcium). Produced the drug in a 4% solution in vials of 5 ml. Can be used as a form of eye drops and podkonyunktivalno injections for treatment of patients suffering from degenerative eye diseases.

Etaden

Enables the biosynthesis of nucleic acids and stimulates the regeneration of the corneal epithelium. Produced the drug in the form of 0,5% eye drops in vials of 5 ml. Manufacturer - Tatkhimpharmpreparaty.

Hemoderivate

Stimulates the regeneration of corneal epithelium integrity is compromised as a result of mechanical trauma, chemical burns or disease. Produced the drug in the form of 20% of the eye gel, 10% and 20% solution for infusion, as well as solutions for injection firms «Solco» and «Polfa» called solcoseryl, and firm «Nicomed» - Actovegin.

Korneregel

Existing Home - Panthenol. How provitamin quickly penetrates into corneal cells. Activates regeneration and healing. Produced the drug in tubes of 5 and 10 г. manufacturer - company Bausch & Lomb.

Midriatiki and tsikloplegiki

Atropine sulfate

The drug prolonged holinoliticheskoy action. Blocks action of acetylcholine and parasimpatomimeticheskih funds. It acts directly on smooth muscles and secretory glands, which are innervated by cholinergic nerve fibers. Contraindicated in patients with glaucoma. It penetrates through the blood-brain barrier and in overdose can cause a number of complications: motor and mental excitement, convulsions, hallucinations. In addition, because of the strong influence on the peripheral M-cholinergic receptors can reduce salivation and to strengthen the heartbeat. Skin age in some patients allergic dermatitis. Usually used in the form of 0,1% and 0,5% and 1% eye drops. Begins to work through 45-100 min. after installation. Cycloplegia occurs after 1-3 hours and lasts up to 12-14 days. Applied mainly in the treatment of inflammatory diseases of the vascular membrane of the eye, rarely - in order to complete relaxation of accommodation.

Gomatropina hydrobromide

The drug, which pharmacologically similar to atropine, but less active. Can be used in the form of 0,25% -0,5% -1% and 2% aqueous solutions for installations in the eye. Pupil dilation and mild cycloplegic occur within 30-60 minutes and completely disappear after 10-20 hours. Contraindicated in patients with glaucoma. Manufacturer - Company Medical Ophthalmics.

Tropicamide

The drug, which blocks cholinergic stimulation of the sphincter muscles, and ciliated. It is intermittent mydriasis (after 20-40 minutes after the installation). Duration of up to 4-6 hours. Producing it in the form of 0,5% and 1% eye drops. Contraindicated in patients with glaucoma. Trade name - Midriatsil (company Alcon) and Tropicamide (company Ciech-Polfa Group).

Tsiklopentolata hydrochloride

The product belongs to the M-holinoblokatoram, but short-acting. It is for 6-12 hours, and mydriasis in 24 hours cycloplegic. Pharmacological effect occurs within a 15-30 minutes after a single installation of drops in the conjunctival cavity. However, it should be borne in mind that the magnitude of residual accommodation in patients with light iris can be up to 1.0 diopters, and with the dark - 2,0-4,0 dpt. The drug is contraindicated in patients with glaucoma and patients with narrow angle of anterior chamber of the eye. I do not recommend using it when working with children under 3 months. Patients who are sensitive to tsiklopentolatu, you may receive complaints of physical weakness, nausea, psihoasteniyu, inexplicable tearfulness, reduced memory, poor orientation in space and time. Produced the drug in the form of 0,5%, 1% and 2% eye drops. Trade name - Tsiklomed. Manufacturer - Company Promed Exports.

Mestnoanesteziruyuschih funds

The historical aspect of the priority here belongs to cocaine - alkaloids isolated from leaves Erythroxylon Coca. On the possibility of its use for anesthesia integumentary tissues of the eye was first reported K. Koller September 15, 1884 at the Congress of Ophthalmologists in Gaydelberge. Then, in the same year, N. Knarr already started to produce complex operations on the eyeball under the protection of anesthetic 4% solution of cocaine, injectable retrobulbarno. All local anesthetics inhibit the excitation of sensory receptors, thus preventing the possibility of a flow of painful afferent impulses. The duration of their action is determined by the degree of lipid solubility, and both of these figures are directly proportional. A general disadvantage of local anesthetics is that they violate in some way the integrity of the corneal epithelium.

Dicaine

The drug is used in the form of 0,25% and 0,5% eye drops or ophthalmic medicinal films (the latter in combination with sulfapiridazin sodium and atropine sulfate). Manufacturer - Organics.

Lidocaine

Eye drops (0.5%) containing 1 ml of 20 or 40 mg of active substance. Producing in tubes, droppers, 1,5 ml. For wiring and / or infiltration anesthesia is used 1% and 2% of its solution in ampoules of 5 and 10 ml.

Alkain

Eye drops (0.5%), containing 1 ml of 5 mg of active substance (proparakaina hydrochloride) and preservative. Producing it in bottles of 15 ml. Manufacturer - company Alcon.

Inokain

Eye drops (0.4%), the active ingredient - oksibuprokain. The drug rapidly accumulates in the cells of the corneal epithelium and provides 10-15 minutes to the effect of anesthesia. In rare cases, can cause the development of an allergic reaction of immediate type in the form of keratitis, iritis, dermatitis. Producing it in vials of 5 ml. Manufacturer - Promed Exports.

Tumors of the eye orbit

Dermoid cyst

Congenital neoplasm. Develops from the epithelial cells located at the subperiosteal bone joints orbit, mostly in the upper-inner quadrant. Symptoms: A local non-inflammatory edema of the century. On palpation there is still determined painless education yellowish color (contains cholesterol crystals). Surgical Treatment - subperiosteal orbitotomiya. Weather favorable.

Cholesteatoma (epidermoid cyst)

Develops in middle-aged people at the top or upper-outer wall of the orbit, which is partially lysed. Here subperiosteal accumulates yellowish mass. The eyeball is displaced medially.Gradually developing exophthalmos. Surgical treatment. Weather favorable.

Cavernous hemangioma

A tumor consisting of dilated vessels surrounded psevdokapsuloy. Usually it is the cavernous type. Symptoms: slow growing exophthalmos, the eyeball is not changed, but the fundus tortuous and dilated veins in the retina. You can detect the presence of folds in the glassy plate choroid (the result of pressure of the tumor on the sclera). In other cases, when the cavernous site is localized at the top of the orbit, developed congestive optic disk or downward its atrophy.Surgical treatment. Localization and tumor size is adjusted with computer tomography.

Glioma of the optic nerve

Usually develops in children. It consists of astrocytes, oligodendrocytes and macroglia. Grows slowly. Never fails to germinate the dura mater of the nerve, but its trunk may extend into the cranial cavity. Symptoms: gradually progressive decline in visual acuity, appearance of a painless exophthalmos axial or lateral displacement. At the fundus of the eye develops over time picture of stagnant optic nerve atrophy or his descendants. Diagnosis of the disease set by computer tomography. Treatment of multi-pronged: while preserving the view - radiation therapy, otherwise - surgical. If the tumor does not extend beyond the orbit, it needs to be removed along with the eye. When she enters the channel of the optic nerve, and even more still further intervention plan should be defined neurosurgeon.

Meningioma of the optic nerve

The tumor develops from the arachnoid villi of the nerve. Able to germinate his soft skin and spread to the soft tissue of orbit. It can also penetrate into the cranial cavity. Symptoms: reduced vision, exophthalmos. At the fundus picture of stagnant optic nerve. Diagnosis is difficult even for a CT scan. Treatment of surgical or radiation therapy. Forecast for an unfavorable view.

Neurinoma

The tumor usually comes from the trunks of some nerves - ciliated, supratrochlear and supraorbital passing through the cavity of the eye sockets. It is usually located under the upper orbital wall and the capsule is separated. Symptoms: non-inflammatory swelling of the upper eyelid with the development of partial ptosis, pain in the affected zone. A little later the appearance of axial exophthalmos or lateral displacement of the eyeball. At the fundus edema of the optic disk. For diagnostic purposes, displaying an ultrasound scan of the orbit and computed tomography. Surgical treatment.

Sarcomas

Aggressive tumors, whose source may be any tissue of orbit. At least 25% of malignant tumors considered localization. There are people of different age groups. The greatest danger is rhabdomyosarcoma. Most often it is localized in the upper-inner quadrant of the orbit and affects the upper eyelid levator and upper line of the eye muscles. Symptoms: ptosis, displacement of the eyeball downwards and outwards down a restriction on his mobility. Have quickly developed exophthalmos with congestive expansion episkleralnyh veins. Due to the incomplete closure days in the cornea may appear infiltrates. At the fundus picture of stagnant optic nerve. For diagnosis is necessary to use the results of an ultrasound scan of orbit and computed tomography. Combination Treatment: chemotherapy, after which the external irradiation of orbit.

Lymphoma

The tumor often develops on the background of autoimmune diseases, immunodeficiency states and in leukemia. It consists of lymphoid elements, mainly B-cell origin, and plasma cells.Develops in people of different ages. Symptoms: sudden appearance of exophthalmos with noninflammatory edema of the surrounding tissues and sometimes the development of ptosis. In this case, the palpebral fissure is narrowed. Reposition the eyeball is difficult, then impossible.At the fundus of stagnation. Treatment: external irradiation effectively orbit.