What are eye muscles? Anatomy of the extrinsic muscles of the eye. What are the structural features

The eye must learn to see, just as the tongue learns to speak.

D. Diderot

The oculomotor apparatus is a complex sensorimotor mechanism, the physiological significance of which is determined by its two main functions: motor (motor) and sensory (sensitive).

The motor function of the oculomotor system ensures the guidance of both eyes, their visual axes and the central fossae of the retinas to the object of fixation; the sensory function ensures the merging of two monocular (right and left) images into a single visual image.

The innervation of the extraocular muscles by the cranial nerves determines the close connection between neurological and ocular pathologies, as a result of which an integrated approach to diagnosis is necessary.

18.1. Anatomical and physiological features

Movements of the eyeball are carried out with the help of six extraocular muscles: four straight muscles - external and internal (m. rectus externum, m. rectus internum), upper and lower (m. rectus superior, m. rectus inferior) and two obliques - upper and lower ( m. obliguus superior, m. obliguus inferior).

All straight And superior oblique muscle begin at the tendon ring located around the optic nerve canal at the apex of the orbit and fused with its periosteum (Fig. 18.1). The rectus muscles in the form of ribbons are directed anteriorly to the parallel

along the corresponding walls of the orbit, forming the so-called muscular funnel. At the equator of the eye, they pierce Tenon’s capsule (the vagina of the eyeball) and, before reaching the limbus, they are woven into the superficial layers of the sclera. Tenon's capsule supplies the muscles with a fascial covering that is missing in the proximal region where the muscles begin.

Superior oblique muscle originates from the tendon ring between the superior and internal rectus muscles and goes anteriorly to the cartilaginous block located in the superior internal corner of the orbit at its edge. At the pulley, the muscle turns into a tendon and, passing through the pulley, turns posteriorly and outward. Located under the top line

Rice. 18.1. Muscles of the eye [Broshevsky T.I., Bochkareva A.A., 1983].

muscle, it is attached to the sclera outward from the vertical meridian of the eye. Two-thirds of the entire length of the superior oblique muscle is between the apex of the orbit and the trochlea, and one-third is between the trochlea and its attachment to the eyeball. This part of the superior oblique muscle determines the direction of movement of the eyeball during its contraction.

Unlike the five muscles mentioned inferior oblique muscle begins at the lower inner edge of the orbit (in the area of the entrance of the nasolacrimal canal), goes posteriorly outward between the orbital wall and the inferior rectus muscle towards the external rectus muscle and is fan-shaped attached under it to the sclera in the posteroexternal part of the eyeball, at the level of the horizontal meridian of the eye.

Numerous cords extend from the fascial membrane of the extraocular muscles and Tenon’s capsule to the orbital walls.

The fascial-muscular apparatus ensures a fixed position of the eyeball and gives smoothness to its movements.

The muscles of the eye are innervated by three cranial nerves:

Oculomotor nerve - n. oculomotorius (III pair) - innervates the internal, superior and inferior rectus muscles, as well as the inferior oblique;

Trochlear nerve - n. trochlearis (IV pair) - superior oblique muscle;

Abducens nerve - n. abducens (VI pair) - external rectus muscle.

All these nerves pass into the orbit through the superior orbital fissure.

The oculomotor nerve, after entering the orbit, divides into two branches. The superior branch innervates the superior rectus muscle and the levator palpebrae superioris, the inferior branch innervates the internal and inferior rectus muscles, as well as the inferior oblique.

The nucleus of the oculomotor nerve and the nucleus of the trochlear nerve located behind and next to it (provides the work of the oblique muscles) are located at the bottom of the aqueduct of Sylvius (aqueduct of the brain). The nucleus of the abducens nerve (provides the work of the external rectus muscle) is located in the pons under the bottom of the rhomboid fossa.

The rectus oculomotor muscles are attached to the sclera at a distance of 5-7 mm from the limbus, the oblique muscles - at a distance of 16-19 mm.

The width of the tendons at the muscle attachment site ranges from 6-7 to 8-10 mm. Of the rectus muscles, the widest tendon is the internal rectus muscle, which plays a major role in the function of bringing together the visual axes (convergence).

The line of attachment of the tendons of the internal and external muscles, i.e., their muscular plane, coincides with the plane of the horizontal meridian of the eye and is concentric with the limbus. This causes horizontal eye movements, their casting, turn to the nose - adduction with contraction of the internal rectus muscle and lead, turn to temple - abduction with contraction of the external rectus muscle. Thus, these muscles are antagonistic in nature.

The superior and inferior rectus and oblique muscles perform mainly vertical movements of the eye. The line of attachment of the superior and inferior rectus muscles is located somewhat obliquely, their temporal end is further from the limbus than the nasal end. As a result, the muscular plane of these muscles does not coincide with the plane of the vertical meridian of the eye and forms an angle with it, equal to an average of 20 o and open to the temple.

This attachment ensures rotation of the eyeball during the action of these muscles not only upward (with contraction of the superior rectus

muscles) or downward (with contraction of the inferior straight line), but simultaneously inwardly, i.e. adduction.

The oblique muscles form an angle of about 60° with the plane of the vertical meridian, open to the nose. This determines the complex mechanism of their action: the superior oblique muscle lowers the eye and produces its abduction (abduction), the inferior oblique muscle is an elevator and also an abductor.

In addition to horizontal and vertical movements, these four vertically acting oculomotor muscles perform torsional eye movements clockwise or counterclockwise. In this case, the upper end of the vertical meridian of the eye deviates towards the nose (intrusion) or towards the temple (extortion).

Thus, the extraocular muscles provide the following eye movements:

Adduction (adduction), i.e. its movement towards the nose; this function is performed by the internal rectus muscle, additionally by the superior and inferior rectus muscles; they are called adductors;

Abduction (abduction), i.e. movement of the eye towards the temple; this function is performed by the external rectus muscle, additionally by the superior and inferior oblique muscles; they are called abductors;

Upward movement - under the action of the superior rectus and inferior oblique muscles; they are called lifters;

Downward movement - under the action of the inferior rectus and superior oblique muscles; they are called lowerers.

The complex interactions of the oculomotor muscles are manifested in the fact that when moving in some directions they act as synergists (for example, partial adductors - the superior and inferior rectus muscles, in others - as antagonists).

nists (upper straight line - lifter, lower straight line - lowerer).

The extraocular muscles provide two types of conjugal movements of both eyes:

Unilateral movements (in the same direction - right, left, up, down) - so-called version movements;

Opposite movements (in different directions) are vergent, for example, to the nose - convergence (bringing together the visual axes) or to the temple - divergence (spreading the visual axes), when one eye turns to the right, the other to the left.

Vergence and version movements can also be performed in the vertical and oblique directions.

The functions of the oculomotor muscles described above characterize the motor activity of the oculomotor apparatus, while the sensory one is manifested in the function of binocular vision.

Binocular vision, i.e. vision with two eyes, when an object is perceived as a single image, is possible only with clear conjugal movements of the eyeballs. The eye muscles ensure that the two eyes are positioned on the object of fixation so that its image falls on identical points in the retinas of both eyes. Only in this case does a single perception of the object of fixation occur. Identical, or corresponding, are the central foveae and points of the retina, located at the same distance from the central fovea in the same meridian. The points of the retina, located at different distances from the central fovea, are called disparate, inappropriate (non-identical). They do not have the innate property of single perception. When the image of the object of fixation hits non-identical points of the retina, double vision occurs,

or diplopia (Greek diplos - double, opos - eye) is a very painful condition. This occurs, for example, with strabismus, when one of the visual axes is shifted to one side or the other from the common point of fixation.

The two eyes are located in the same frontal plane at a certain distance from each other, so in each of them not quite identical images of objects located in front and behind the object of fixation are formed. As a result, double vision inevitably occurs, called physiological. It is neutralized in the central section of the visual analyzer, but serves as a conditioned signal for the perception of the third spatial dimension, i.e. depth.

Such a displacement of images of objects (closer and farther from the point of fixation) to the right and left of the macula on the retinas of both eyes creates the so-called transverse disparation (displacement) of the images and their entry (projection) onto disparate areas (non-identical points), which causes double vision , including physiological.

Transverse disparity is the primary factor in depth perception. There are secondary, auxiliary factors that help in assessing the third spatial dimension. This is linear perspective, the size of objects, the location of light and shadow, which helps the perception of depth, especially in the presence of one eye, when transverse disparity is excluded.

The concept of binocular vision is associated with terms such as fusion(psychophysiological act of merging monocular images), fusion reserves, providing binocular fusion with a certain degree of convergence (convergence) and separation (divergence) of the visual axes (see Chapter 3).

18.2. Pathology of the oculomotor system

Disturbances in the function of the oculomotor system can manifest themselves in incorrect position of the eyes (strabismus), limitation or absence of their movements (paresis, paralysis of the extraocular muscles, etc.), and impaired fixation ability of the eyes (nystagmus).

Strabismus is not only a cosmetic defect, but is also accompanied by a pronounced disorder of monocular and binocular visual functions, depth vision, and diplopia; it complicates visual activity and limits a person’s professional capabilities.

Nystagmus often leads to low vision and visual impairment.

18.2.1. Strabismus

Strabismus (strabismus, heterotopia) is a deviation of one eye from the common point of fixation, accompanied by impaired binocular vision. This disease manifests itself not only in the formation of a cosmetic defect, but also in the disturbance of both monocular and binocular visual functions.

Strabismus is polyetiological. The cause of its development may be ametropia (hypermetropia, myopia, astigmatism), anisometropia (different refraction of the two eyes), uneven tone of the extraocular muscles, impaired function, diseases leading to blindness or a significant decrease in vision in one eye, congenital malformations of the binocular vision mechanism. All these factors influence the still unformed and insufficiently stable mechanism of binocular fixation in children and in the case of exposure to non-

favorable factors (infectious diseases, stress, visual fatigue) can lead to strabismus.

There are two types of strabismus - friendly and unfriendly (for example, paralytic), which differ both in pathogenesis and clinical picture.

Hidden and imaginary strabismus should be distinguished from true strabismus.

18.2.1.1. Hidden strabismus, or heterophoria

The ideal muscular balance of both eyes is called orthophoria (from Greek ortos - straight, correct). In this case, even when the eyes are separated (for example, by covering them), their symmetrical position and binocular vision are maintained.

The majority (70-80%) of healthy people experience heterophoria (from the Greek heteros - other), or hidden squint. With heterophoria, there is no ideal balance of the functions of the oculomotor muscles, however, the symmetrical position of the eyes is maintained due to the binocular fusion of visual images of both eyes.

Heterophoria can be caused by anatomical or neural factors (structural features of the orbit, tone of the extraocular muscles, etc.). Diagnosis of heterophoria is based on excluding conditions for binocular vision.

A simple way to determine heterophoria is the cover test. The subject fixes an object (the end of a pencil, the researcher’s finger) with both eyes, then the doctor covers one of his eyes with a shutter. In the presence of heterophoria, the closed eye will deviate in the direction of action of the predominant muscle: medially (with

esophoria) or outward (with exophoria). If the shutter is removed, this eye, due to the desire for binocular fusion (precluded when it is covered), will make an adjustment movement to the starting position. In case of orthophoria, the symmetrical position of the eyes will be preserved.

With heterophoria, no treatment is required; only if it is significant, binocular decompensation and asthenopia (pain in the eye area, eyebrows) may occur. In these cases, glasses that facilitate vision (spherical or prismatic) are prescribed.

18.2.1.2. Imaginary strabismus

Most people have a small angle (3-4°) between the optical axis passing through the center of the cornea and the nodal point of the eye, and the visual axis running from the central fovea of the macula to the object of fixation - the so-called gamma angle (γ). In some cases, this angle reaches 7-8 o or more. When examining such patients, the light reflex from the ophthalmoscope on the cornea is shifted from its center to the nose or temple, resulting in the impression of strabismus. The correct diagnosis can be established after determining binocular vision: with imaginary strabismus, binocular vision is present and no treatment is required.

18.2.1.3. Concomitant strabismus

Concomitant strabismus is a pathology observed mainly in childhood, the most commonly developing form of oculomotor disorders, which, in addition to deviation of the eye from the general point of fixation, is characterized by impaired binocular vision. It is detected in 1.5-3.5% of children. With a friendly oblique

ocular functions of the extraocular muscles are preserved, in this case, one eye will be fixing, the other - squinting.

Depending on the direction of deviation of the squinting eye, they distinguish between convergent strabismus (esotropia), divergent strabismus (exotropia), and vertical strabismus when one eye deviates up or down (hyper- and hypotropia). With torsional displacements of the eye (inclination of its vertical meridian towards the nose or temple) they speak of cyclotropia (ex- and incyclotropia). Combined strabismus is also possible.

Of all the types of concomitant strabismus, the most commonly observed are convergent(70-80% of cases) and divergent(15-20%). Vertical and torsional deviations are observed, as a rule, with paretic and paralytic strabismus.

Based on the nature of the deviation of the eye, they are classified as one-sided, i.e. monolateral, strabismus, when one eye constantly squints, and alternating, in which one or the other eye squints alternately.

Depending on the degree of participation of accommodation in the occurrence of strabismus, there are accommodative, partially accommodative And non-accommodative strabismus. The impulse to accommodation is increased with hypermetropia and decreased with myopia. Normally, there is a certain connection between accommodation and convergence, and these functions are carried out simultaneously. With strabismus, their relationships are disrupted. The increased impulse to accommodation in hypermetropia, most often observed in childhood, increases the incentive to convergence and causes a high incidence of convergent strabismus.

Accommodative strabismus (more than 15% of patients) is characterized by the fact that deviation (deviation of the eye) is eliminated with optical correction of ametropia, i.e.

proper wearing of glasses. In this case, binocular vision is restored quite often and patients do not need surgical treatment. In the case of non-accommodative strabismus, wearing glasses does not eliminate the deviation and treatment must necessarily include surgery. With partial accommodative strabismus, wearing glasses reduces but does not completely eliminate the deviation.

Strabismus can also be constant or periodic, when the presence of deviation alternates with a symmetrical position of the eyes.

Concomitant strabismus is accompanied by the following sensory disturbances: decreased visual acuity, eccentric fixation, functional scotoma, diplopia, asymmetric binocular vision (abnormal retinal correspondence), impaired depth vision.

One of the most frequently occurring sensory disorders in monolateral strabismus is amblyopia, i.e., a functional decrease in vision of the eye due to its inactivity and disuse.

According to the degree of decrease in visual acuity, according to the classification of E. S. Avetisov, low degree amblyopia is distinguished - with visual acuity of the squinting eye 0.8-0.4, average - 0.3-0.2, high - 0.1-0, 05, very high -0.04 and below. High degree amblyopia is usually accompanied by impaired visual fixation of the squinting eye.

Normal fixation is foveal (Fig. 18.2). Non-central fixation can be parafoveal, macular, paramacular, peridiscal (peripheral), and the image falls on an eccentric area of the retina.

According to the mechanism of occurrence, amblyopia can be disbinocular, i.e. arising as a result binocular vision disorders,

Rice. 18.2.Topography of visual fixation based on the fundus image on a monobinoscope.

what is observed with strabismus, when the participation of the deviated eye in the visual act is significantly reduced, or refractive, which is a consequence of untimely prescription and inconsistent wearing of glasses during ametropia, creating a blurry image in the fundus.

In the presence of uncorrected anisometropia, anisometropic amblyopia. Refractive amblyopia can be quite successfully overcome through rational and permanent optical correction (glasses, contact lenses).

Cloudiness of the eye media (congenital cataract, cataract) can cause obscuration amblyopia, which is difficult to treat, the elimination of which requires timely surgical intervention (for example, extraction of congenital cataracts, corneal transplantation).

Amblyopia can be unilateral or bilateral.

Amblyopia also reduces color and contrast sensitivity.

When strabismus appears, double vision inevitably occurs, since the image in the squinting eye falls on a disparate area of the retina, however, thanks to the adaptation

Through these mechanisms, the visual-nervous system adapts to the asymmetrical position of the eyes and functional suppression, inhibition, or “neutralization” [in the terminology of L. I. Sergievsky (1951)] occurs of the image in the squinting eye. Clinically, this is expressed in the appearance of a functional scotoma. Unlike true scotomas observed with organic lesions of the organ of vision, a functional scotoma with strabismus exists only if both eyes are open and disappears with monocular fixation (when the other eye is closed). Functional scotoma is a form of sensory adaptation that relieves double vision, which is observed in most patients with concomitant strabismus.

With monolateral strabismus, the presence of a permanent scotoma in the squinting eye leads to a persistent decrease in vision. In the case of alternating strabismus, the scotoma appears alternately in the right and then in the left eye, depending on which eye is in this moment squints, so amblyopia does not develop.

One of the forms of sensory adaptation in concomitant strabismus is the so-called abnormal retinal correspondence,

or asymmetric binocular vision. Diplopia disappears due to the appearance of the so-called false macula. A new functional connection appears between the central fovea of the fixating eye and the area of the retina of the squinting eye, which receives the image due to deviation (deviation of the eye). This form of adaptation is observed extremely rarely (in 5-7% of patients) and only with small angles of strabismus (microdeviations), when the area of the retina of the deviated eye is organically and functionally little different from the central fovea. At large angles of strabismus, when the image falls on the insensitive peripheral part of the retina, the possibility of its interaction with the highly functional central fovea of the fixating eye is excluded.

Research methods. Assessment of the condition of the oculomotor system involves the study of both sensory (sensitive) and motor (motor) functions.

The study of sensory functions includes the determination of binocular vision and the degree of its stability, depth (or stereoscopic) vision, its acuity, the presence or absence of bifoveal fusion, fusion reserves, functional scotoma of suppression, and the nature of diplopia.

When studying motor functions, the mobility of the eyeballs, the amount of deviation, and the degree of dysfunction of various oculomotor muscles are determined.

When collecting an anamnesis, it is necessary to find out at what age strabismus arose, the presumed cause of its development, the presence of injuries and previous diseases, whether one eye was always squinted or alternating deviation of both eyes was manifested, the nature of the treatment, the duration of wearing glasses.

Study visual acuity should be carried out with or without glasses, as well as with two eyes open, which is especially important for nystagmus.

In addition to general ophthalmological examination, special methods are used.

For determining nature of strabismus(monolateral, alternating) a fixation test should be carried out: cover the fixating (for example, right) eye of the subject with a palm and ask him to look at the end of a pencil or the handle of an ophthalmoscope. When the deviated eye (left) begins to fixate the object, remove the palm and leave the right eye open. If the left eye continues to fixate the end of the pencil, then it means that the subject has alternating strabismus, but if with two eyes open the left eye squints again, then the strabismus is monolateral.

Type of strabismus and the amount of deviation (squint angle) is determined by the direction of eye deviation (convergent, divergent, vertical).

Strabismus angle can be determined using the Hirshberg method. The doctor, applying a manual ophthalmoscope to his eye, asks the patient to look into the opening of the ophthalmoscope and observes the position of the light reflexes on the corneas of both eyes of the patient from a distance of 35-40 cm. The magnitude of the angle is judged by the displacement of the reflex from the center of the cornea of the squinting eye in relation to the pupillary edge iris and limbus (Fig. 18.3) with an average pupil width of 3-3.5 mm. With convergent strabismus, they are oriented along the outer edge of the pupil, and with divergent strabismus, along the inner edge.

Eye mobility determined by moving the object of fixation, which is followed by the patient’s eyes, in eight directions of gaze: right, left, up, down,

Rice. 18.3.The position of the light reflex on the cornea of a squinting eye when determining the angle of strabismus using the Hirshberg method.

up - right, up - left,

down - right, down - left. With concomitant strabismus, the eyes move in a fairly full range. For paralytic strabismus, it is advisable to use special methods - co-ordimetry And provoked diplopia(see section 18.2.1.4) to identify the affected muscle.

In case of vertical deviation, the angle of strabismus is determined in the lateral positions - during adduction and abduction. An increase in the angle of vertical strabismus during adduction indicates damage to the oblique muscles, and during abduction - to the vertical rectus muscles.

In the presence of amblyopia, the state of visual fixation is assessed using a monobinoscope (Fig. 18.4) - one of the main instruments used for the study and treatment of strabismus. The device is designed like a stationary Gulstrand ophthalmoscope, which allows, when fixing the child’s head, to examine the fundus of the eye, determine the state of visual fixation, and carry out therapeutic procedures. The child looks at the end of the fixation rod (“needle”) of the monobinoscope, the shadow from which is projected (on the fundus) onto the fixation site (see Fig. 18.2).

Research methods binocular functions for strabismus are based on the principle separation of fields of view right and left eyes (haploscopy), which makes it possible to identify the participation (or non-participation) of the squinting eye in binocular vision. Haploscopy can be mechanical, color, raster, etc.

One of the main haploscopic devices is the synoptophore (Fig. 18.5). The visual fields of the right and left eyes are separated in this device mechanically, using two (separate for each eye) movable optical tubes, with the help of which

Rice. 18.4.Determination of visual fixation and exercises on a monobinoscope.

Rice. 18.5.Synoptophore lessons.

The subject is presented with paired test objects.

Test objects of the synoptophore (Fig. 18.6) can be moved (horizontally, vertically, torsionally, i.e. clockwise and counterclockwise) and installed in accordance with the angle of strabismus. They differ in the control elements for each eye, which allows, when combining paired (right and left) patterns, to judge the presence or absence of binocular fusion, i.e. fusion, and in its absence, the presence of a functional scotoma (when a detail or the entire pattern disappears before the squinting eye). If there is a fusion, fusion reserves are determined by bringing together or spreading test objects (optical tubes of the synoptophore) until the test doubles.

object. When the synoptophore tubes are brought together, positive fusion reserves (convergence reserves) are determined, when separated, negative fusion reserves (divergence reserves) are determined.

The most significant are positive fusion reserves. When studied on a synoptophore with test No. 2 (“cats”) in healthy individuals, they are 16 ± 8 o, negative - 5 ± 2 o, vertical - 2-4 prism diopters (1-2 o). Torsion reserves are: incycloreserves (when the vertical meridian of the pattern is tilted towards the nose) - 14 ± 2 o, excycloreserves (when tilted towards the temple) - 12 ± 2 o.

Fusion reserves depend on the research conditions (using different methods - synoptophore or prism), the size of the test

Rice. 18.6.An example of combining two images on a synoptophore.

Rice. 18.7. Four-point color test for studying binocular vision and red-green glasses filters.

objects, their orientation (vertical or horizontal) and other factors that are taken into account when determining treatment tactics.

To study binocular vision in natural and similar conditions, methods based on color, polaroid or raster division of visual fields are used. For this purpose, for example, red and green light filters are used (red - in front of one eye, green - in front of the other eye), polaroid filters with vertically and horizontally oriented axes, raster filters of mutually perpendicular orientation for both eyes. The use of these methods allows us to answer the question about the nature of the

the patient’s vision: binocular, simultaneous (diplopia) or monocular.

The Belostotsky-Friedman four-point color test has two green (or blue) circles, one red and one white circle (Fig. 18.7). The subject looks through red-green glasses: there is a red filter in front of the right eye, a green (or blue) filter in front of the left eye. The middle white circle, seen through the red and green filters of the glasses, will be perceived as green or red depending on the dominance of the right or left eye (Fig. 18.8). With monocular vision of the right eye (Fig. 18.8, a) through the red glass, the subject sees only red circles (there are two of them), with monocular vision of the left eye (Fig. 18.8, b) - only green circles (there are three of them). With simultaneous vision (Fig. 18.8, c) he sees five circles: two red and three green, with binocular vision (Fig. 18.8, d, e) he sees four circles: two red and two green.

When using polaroid or raster filters (the so-called Bagolini glasses), as in a color device, there is a common object to merge and objects visible only to the right or only to the left eye.

Methods for studying binocular vision differ in the degree of uncoupling (“dissociating”) action: it is more pronounced in a color device, less in the Polaroid test and in raster glasses.

Rice. 18.8. Patient-visible arrangement of four-point color test circles. Explanation in the text.

kakh, since the conditions for vision in them are closer to natural.

When using raster glasses, the entire surrounding space is visible, as in natural conditions (unlike vision in red-green color glasses), and the dissociating effect of rasters is manifested only by thin, mutually perpendicular light strips passing through a common round light source - the object of fixation. Therefore, when examining with different methods in the same patient, it is possible to identify simultaneous vision using a four-point test and binocular vision using Bagolini raster glasses. This must be remembered when assessing binocular status and to determine treatment tactics.

There are various depth-measuring instruments and stereoscopes that allow you to determine the acuity and thresholds (in degrees or linear quantities) of depth and stereoscopic vision. In this case, the examinee must correctly evaluate or position the presented test objects, shifted in depth. The degree of error will determine the acuity of stereo vision in angular or linear quantities.

Divergent concomitant strabismus is a more favorable form of oculomotor disorders than convergent strabismus; it is less often accompanied by amblyopia. Impaired binocular vision manifests itself in divergent strabismus in a milder form; convergence insufficiency is mainly detected.

Treatment. The ultimate goal of treatment for concomitant strabismus is the restoration of binocular vision, since only under this condition visual functions are restored and asymmetry in eye position is eliminated. For this purpose, a system of complex treatment of concomitant strabismus is used, which includes:

Optical correction of ametropia (glasses, contact lenses);

Pleoptic treatment (pleoptics - treatment of amblyopia);

Surgery;

Orthoptodiploptic treatment aimed at restoring binocular functions (pre- and postoperative) and depth vision.

Optical correction. Optical correction of ametropia helps restore visual acuity and normalize the ratio of accommodation and convergence. This leads to a reduction or elimination of the angle of strabismus and ultimately helps to restore binocular vision (with accommodative strabismus) or create conditions for this. Correction of ametropia is indicated for any form of strabismus. Glasses should be prescribed for constant wear under systematic monitoring of visual acuity (once every 2-3 months).

Pleoptics. Pleoptics is a system of methods for treating amblyopia.

One of the traditional and main methods of pleoptic treatment is direct occlusion - turning off the healthy (fixing) eye 1. It creates conditions for fixing objects with the squinting eye, including it in active visual activity and in a significant number of cases, especially when prescribed in a timely manner, leads to the restoration of visual acuity of the squinting eye. For this purpose, special plastic occluders are used, attached to spectacle frames, or homemade soft curtains (curtains), as well as translucent (with varying degrees of density) occluders. As the visual acuity of the amblyopic eye increases, the degree of transparency of the occluder in front of the dominant eye

1 Occlusion as a method of treating amblyopia was proposed in 1751 by the French researcher Buffon.

can be increased. Translucent occlusion also promotes the development of binocular coordination in both eyes. The occlusion mode is determined by the doctor. Occlusion is prescribed for the whole day (the occluder is removed at night), for several hours a day or every other day, depending on the degree of decrease in visual acuity.

It should be remembered that direct occlusion can lead to dysfunction and reduction of binocular cortical neurons, resulting in deterioration of binocular vision, so they use the tactic of a gradual transition to other treatment methods or the use of penalization. The principle of penalization (from the French penalite - fine, penalty) is to create artificial anisometropia in the patient using special temporary glasses. The reason for developing the method was the observation of French researchers (Pfandi, Pouliquen and Quera), who noted that amblyopia is absent in anisometropia against the background of mild myopia in one eye and emmetropia or mild hypermetropia in the other eye.

Penal glasses penalize the better seeing eye. They are selected individually, while artificially created anisometropia, for example, by overcorrection (by 3.0 diopters) of the better eye with plus lenses, sometimes in combination with its atropinization. As a result of this, the dominant eye becomes myopic and its distance vision deteriorates, while the amblyopic eye is connected to active work through full optical correction. At the same time, unlike direct occlusion, the possibility of vision with two eyes is preserved, so penalization is more physiological, but it is more effective at an earlier age - 3-5 years.

In combination with occlusion or separately, methods of light stimulation of the amblyopic eye are used:

the method of local “blinding” irritation of the central fovea of the retina with light, developed by E. S. Avetisov, the method of sequential visual images according to Küppers, illumination of the paracentral area of the retina (the area of eccentric fixation) according to the Bangerter method. These methods provide a disinhibitory effect and remove the phenomenon of suppression from the central zone of the retina.

The method is chosen depending on the child’s age, characteristics of his behavior and intelligence, and the state of visual fixation.

For treatment using the Avetisov method, which can be combined with direct occlusion, various brightness sources are used: light guide, laser light. The procedure lasts several minutes, so it can be used in young children.

Küppers' method of sequential images is based on their excitation by illuminating the fundus while simultaneously darkening the fovea with a round test object. Consecutive visual images after illumination are observed on a white screen, and their formation is stimulated by intermittent illumination of the screen. When using this method, higher demands are placed on the patient’s intelligence than when treated using the Avetisov method.

Treatment with the indicated methods, as well as with the use of general illumination, illumination through a red filter and their other varieties, is carried out on monobinoscope. The device allows, when fixing the child's head, to conduct an examination of the fundus of the eye, visual fixation, pleoptic and diploptic treatment under the control of ophthalmoscopy.

All of the above methods must be used in combination with active household visual training (drawing

learning, playing with small parts such as “Mosaic”, “Lego”, etc.).

Laser radiation is used in pleoptic treatment in the form of reflected laser light, so-called speckles, by observing the laser “grain”, which has a stimulating effect on the retina. They use domestic devices “LAR” and “MAKDEL”: the first is remote, the second is put to the eyes. Laser speckle can also be used on a monobinoscope.

The listed methods make it possible to influence mainly the light and brightness sensitivity of the eye. The complex impact on different kinds sensitivity in amblyopia is successfully carried out using dynamic color and frequency-contrast stimuli of varying brightness, shape and semantic content. This is implemented in special domestic computer programs “EUE” (exercises “Shooting Range”, “Chase”, “Crosses”, “Spider”, etc.). The exercises are interesting for children and require their active participation. Stimulus tests are dynamic and easy to change. The principle of dynamic change of color and contrast-frequency stimuli is also used in the method based on the phenomenon of interference of polarized light by A. E. Vakurina. The complex effect on various types of visual sensitivity significantly increases the effectiveness of pleoptic treatment.

Surgery. For strabismus, the goal of surgery is to restore the symmetrical or nearly symmetrical position of the eyes by changing the muscle balance. Strengthen weak ones or weaken them strong muscles.

Operations that weaken the action of muscles include recession (transfer of the muscle attachment site posteriorly from the anatomical one), partial myotomy (applying

pepper edge notches on both sides of the muscle), lengthening of the muscle through various plastic manipulations), tenotomy (intersection of the muscle tendon). Currently, tenotomy is practically not used, since it can lead to a sharp limitation of the mobility of the eyeball and exclude the possibility of restoring visual functions.

In order to enhance the action of the muscle, a section of the muscle is resected (4-8 mm long, depending on the degree of dosage of the intervention and the size of the strabismus angle) or the formation of a muscle fold or a muscle tendon fold - tenorrhaphy, as well as moving the attachment point of the muscle anteriorly (anteposition). With convergent strabismus, the internal rectus muscle is weakened and the external rectus muscle is strengthened; with divergent strabismus, the opposite actions are performed.

The basic principles of performing surgical intervention for strabismus are as follows.

It is necessary to abandon forced interventions and observe the principle of preliminary dosing of the operation in accordance with existing calculation schemes. The operation is performed in stages: first on one eye, then (after 3-6 months) on the other.

The dosed intervention is evenly distributed over several eye muscles (weakening strong muscles, strengthening weak muscles).

Be sure to maintain the connection between the muscle and the eyeball during surgery on it.

Recovery correct position the eye creates conditions for the restoration of binocular vision, which can ensure self-correction of the residual strabismus angle in postoperative surgery.

Riode. For large strabismus angles (30 o or more), operations are performed in 2 (or 3) stages, depending on the initial value of the strabismus angle.

A high cosmetic and therapeutic effect is observed when using the dosing scheme for the effect of the operation, developed by E. S. Avetisov and Kh. M. Makhkamova (1966). This scheme provides for recession of the internal rectus muscle by 4 mm with a Hirschberg deviation of less than 10 o. A greater degree of recession often leads to limited mobility of the eyeball. At strabismus angles of 10 o, 15 o, 20 o, 25 o, this operation is performed in combination with resection (strengthening) of the antagonist - the external rectus muscle of the same eye - in a dosage of 4-5; 6; 7-8 and 9 mm respectively. If residual deviation persists, the second stage of the operation is performed on the other eye according to a similar dosing regimen no earlier than after 4-6 months. Symmetrical eye position is achieved in 85% of patients or more.

A similar dosing scheme is used in operations for divergent strabismus, but at the same time the external muscle is weakened (causing its recession) and the internal rectus is strengthened.

The indication for the operation is the absence therapeutic effect with constant (for 1.5-2 years) wearing glasses (if indicated).

Usually the operation is performed at the age of 4-6 years, which depends on the time of onset of the disease. In congenital forms of the disease and large eye deviation angles, surgery is performed earlier - at 2-3 years. It is advisable to eliminate strabismus in preschool age, which helps to increase the effectiveness of further functional treatment and has a beneficial effect on the restoration of visual functions.

Orthoptic and diploptic treatment. Orthoptics and diploptics are a system of methods for restoring binocular vision, or rather binocular functions, the elements of which are bifoveal fusion, fusion reserves, relative accommodation, stereo effect, depth perception of space and other functions. Wherein orthoptics is treatment using devices with complete artificial separation of the visual fields of both eyes: each eye is presented separate object and set it at a strabismus angle; Diploptics is treatment in natural and similar conditions.

Binocular exercises are carried out after achieving the maximum possible visual acuity of the squinting eye, however, visual acuity of 0.3-0.4 is acceptable.

Orthoptic exercises

usually performed on devices with mechanical division of fields of view(mechanical haploscopy), the most important of which is the synoptophore (see Fig. 18.5; analogues - amblyophore, orthoamblyophore, synoptophore, etc.). Paired test objects for both eyes are movable and can be positioned at any angle of strabismus. This is a great advantage of the synoptophore over instruments with fixed patterns. Synoptophore has diagnostic and therapeutic purposes. For diagnostic purposes (determination of functional scotoma, bifoveal fusion), test objects for combination (“chicken and egg”) or small (2.5° or 5°) test objects for fusion (“cat with a tail” and “cat with ears"). To determine fusion reserves and for therapeutic purposes, test objects for fusion of large sizes (7.5°, 10°, etc.) are used.

The purpose of the exercises is to eliminate functional scotoma and develop bifoveal fusion (senior

weed fusia). To do this, two types of exercises are used: alternating (alternating) or simultaneous light stimulation (“blinking”). Test objects must be installed at the objective angle of strabismus, then they are projected onto the central fovea of the retina. The device allows you to change the frequency of blinks from 2 to 8 per 1 s, which is consistently increased during the exercises.

The third type of exercise is the development of fusion reserves: horizontal (positive and negative, i.e. convergence and divergence), vertical, cycloreserves (circular). Large tests are used first and then smaller tests are used for merging. Exercises are prescribed both before and after postoperative period and are carried out in courses of 15-20 sessions with an interval of 2-3 months.

Orthoptic devices, for all their attractiveness and necessity (at initial stages treatment) limit the possibility of restoration of binocular

functions in natural conditions and provide cure in only 25-30% of patients, which is due artificial conditions vision on these devices. In this regard, after achieving a symmetrical position of the eyes, treatment should be carried out to restore binocular functions in “free space”, without mechanical separation of the visual fields.

One of these methods is the method of binocular sequential visual images [Kashchenko T. P., 1966]. It allows you to restore bifoveal fusion, eliminate functional scotoma and restore binocular vision. The method can be used in combination with exercises on the synoptophore with symmetrical or close to it eye position in the postoperative period. Follower-

These images (in the form of a circle with a right horizontal mark for the right eye and with a left mark for the left) are evoked, as when using the Küppers method (in the treatment of amblyopia), on a monobinoscope, but both eyes are illuminated, and sequentially: first one, and then another. Then the patient observes the images evoked in each eye on a white screen under intermittent lighting and combines them into a single image. After 1-2 minutes, the illumination procedure is repeated 2 more times. The use of the method of binocular sequential images increases the effectiveness of treatment and helps restore binocular vision.

The shortcomings of orthoptics methods gave rise to the development of another treatment system - diploptics [Avetisov E. S., 1977]. The basic principle of diploptics is to eliminate the phenomenon of suppression of the visual image of a squinting eye in natural conditions by inducing diplopia and developing a fusional bifixation reflex.

All diploptic methods are used with two open eyes, the presence of bifoveal fusion, symmetrical or close to it position of the eyes, achieved through surgery or optical correction. There are a number of diploptic methods, in which various dissociating (“provocative”) techniques are used to induce diplopia.

Restoration of the bifixation mechanism according to the method developed by E. S. Avetisov and T. P. Kashchenko (1976) is carried out using a prism, rhythmically presented in front of one eye for 2-3 s with an interval of 1-2 s. The prism deflects the image of the object of fixation to the paracentral areas of the retina, which causes double vision, which is a stimulus for binocular fusion - the so-called fusion.

Rice. 18.9. A set of prisms for diploptic treatment Diploptic-P and test objects for it.

onny reflex (bifixation). The prism power is successively increased from 2.0-4.0 to 10.0-12.0 diopters. A series of “Diploptic” devices has been developed, which includes a set of prisms (Fig. 18.9). There are devices that allow you to change the strength of the prism and the direction of its base, either towards the nose or towards the temple, in automatic mode.

The method of dissociating accommodation and convergence (the “dissociation” method) “teaches” binocular fusion under conditions of increasing load with negative lenses from 0 to -7.0 diopters with an interval of 0.5 diopters, and then under conditions of sequential relaxation with positive spherical lenses from 0 to +5.0 diopters. The patient overcomes the double vision caused by this. The method promotes the development of not only bifixation and fusion, but also binocular(relative) accommodation, without which binocular vision is impossible. Using the domestic Forbis device, you can train binocular vision and relative accommodation in conditions of color, raster and polaroid separation of visual fields.

Any diploptic exercise is performed for 15-25 minutes, 15-20 lessons are prescribed per course. When performing exercises, carry out

They control binocular vision from different working distances - 33 cm, 1 m, 5 m, with glasses and without glasses. The size of the transferred negative and positive spherical lenses is also controlled. When using the “dissociation” method on a color test for near 33 cm (on the Forbis device), negative reserves normally average +5.0 diopters, positive reserves - up to 7.0 diopters; in patients at the initial stages of treatment they are significantly less and can be approximately +1.0 and -1.0 diopters.

The diploptic method of using color (red, green, etc.) light filters of increasing density is implemented using special rulers - light filters [Kashchenko T. P., Tarastsova M. M., 1980]. The density (or throughput) of light filters differs by an average of 5%. The weakest filter is No. 1 (5% density, or high throughput - up to 95%), the densest is No. 15 (75% density) (Fig. 18.10).

A ruler with light filters is placed in front of one eye of the patient (with both eyes open, as when performing any diploptic exercise) and asked

Rice. 18.10. A set of color filters of increasing density and different wavelengths for diploptic treatment Diploptik-SF.

fix a round luminous test object with a diameter of 1-2 cm, located at a distance of 1-2 m. After double vision occurs, provoked by a color filter, the patient must connect (merge) images of the fixation object that are slightly different in color (for example, white and pink). The density of the color filter is successively increased and binocular fusion is trained on each of them.

For the first time, a ruler with red light filters was used by the Italian scientist V. Bagolini (1966) for diagnostic purposes. In domestic strabology, red light filters are used not only for therapeutic purposes, but also to determine the stability of the achieved binocular vision. The criterion for assessing stability is the density (measured as a percentage) of the light filter at which binocular vision is impaired and double vision occurs.

For therapeutic purposes, a set of neutral (light gray), green (blue), red and yellow light filters is used. If, when presented with red filters (which are also used as diagnostic ones), fusion is difficult to achieve, treatment begins with less dissociating (uncoupling) neutral filters. After achieving binocular fusion on neutral filters (of all degrees of density), green or blue filters are sequentially presented, and then red and yellow filters. This method entered clinical practice as chromatic diploptics.

For binocular training in the diploptic treatment system, computer programs (“EYE, Contour”) are used, based on the color division of visual fields. The exercises are fun, playful, and ensure the active participation of the patient.

Rice. 18.11. Exercises on the binarimeter.

In diploptics, the binarimetry method is also used (L. I. Mogilev, I. E. Rabichev, T. P. Kashchenko, V. V. Solovyova, etc.), which consists of presenting two paired test objects (Fig. 18.11) on a binarimeter in free space. In the process of performing the exercises, the merger of test objects is achieved by reducing the distance between them, bringing them closer and moving away along the axis of the device (search for a comfort zone).

In this case, a third, average binocular image appears - an imaginary one, and in depth it is located closer or further than the ring of the device and can coincide with its plane when the frame with test objects is moved. These exercises develop binocular, depth perception and train relative accommodation.

There are other methods for performing diploptic exercises. Diplopia is induced by creating artificial aniseikonia by enlarging the size of one of the monocular images using a variable magnification lens. Under natural conditions, a difference in image size between the right and left eyes of up to 5% is tolerated; artificially induced aniseikonia in healthy people can be tolerated with a difference in image size of up to

60-70%, and in patients with strabismus only up to 15-20%.

The diploptic method is original, based on the phase (in time) presentation of stimulating tests either for the right or for the left eye.

There is an opinion that visual information is transmitted alternately - either through the right or left visual channel. There is also a certain frequency (“phase”) of such transmission, which is disrupted in various pathological conditions, for example, with strabismus. This is the basis of the method of phase haploscopy using liquid crystal glasses

(ZhKO). When passing electrical impulse Through the plates of such glasses, their transparency changes in a certain frequency-phase mode: one glass will be transparent, the other at this moment will be opaque. The subject does not feel the high frequency of changes in such time phases in the gastrointestinal tract (more than 80 Hz). This is the advantage of LKO compared to other methods of phase presentation of test objects.

These glasses are used in two versions. In the first, the patient must perform fascinating depth exercises “hitting the target” on a computer screen, on which pictures are presented with the same frequency, disparately located for both eyes, which creates the effect of depth. As the exercises are performed, the level of their complexity increases (bringing paired patterns closer together, decreasing depth thresholds), which helps to increase the acuity of depth vision.

In the second option, a liquid-bearing device is used for wearing with an autonomous power supply system. In these glasses, along with the phases alternately presented for each eye, the binocular phase is turned on, when both eyes look through the lens.

pupillary plates of glasses (I. E. Rabichev, T. P. Kashchenko, S. I. Rychkova, P. Shamon), as a result of which the trainee gradually approaches the natural conditions of visual perception.

Diploptic exercises, compared to orthoptic exercises, increase the effectiveness of treatment and contribute to a more significant restoration of binocular vision - from 25-30% (after orthoptics) to 60-65%, and with early use, even more.

Depth vision and stereo vision are trained using various depth-measuring devices and stereoscopes. Exercises using depth devices (a device for throwing balls, a three-stick Howard-Dolman device, a Litinsky device, etc.) are based on the presentation of a real depth difference. During the examination, the patient should not see the ends of the rods of the three-rod device (a movable middle one and two side ones, standing on the same transverse line). After displacement (by the researcher) of the middle rod, the patient must position it using a movable pin in the same row as the side ones. The degree of divergence of the rods determines the acuity of deep vision (in degrees or linear quantities). Normally, the acuity of depth vision when examined from 1-2 m is up to 1-2 cm. Depth vision is well trained in a real environment, for example, in ball games (volleyball, tennis, basketball, etc.).

Research using stereoscopes is based on the presentation of stereopair test objects with disparity (displacement) of varying degrees. They serve to measure the acuity of stereo vision, which depends on the size of the test objects, age and degree of training of the subject. In healthy individuals it is 10-30" (arcseconds).

In diploptic treatment, a certain role is assigned to prismatic glasses. Prismatic lenses are known to refract the light beam, shifting the image of the object of fixation on the retina towards the base of the prism. If there are small or residual strabismus angles in the postoperative period, prismatic glasses are prescribed to be worn along with diploptic treatment. As the angle of strabismus decreases, the power of the prismatic lenses is reduced, and then the glasses are discontinued.

Prisms are also used to develop fusion reserves in “free space”. In this case, it is convenient to use a Landolt-Herschel type biprism, the design of which allows you to smoothly increase (or decrease) its prismatic action by rotating the disk.

Biprism domestic production(OKP - prism ophthalmic compensator) can be fixed in a special device or spectacle frame. Changing the direction of the base of the prism towards the temple promotes the development of positive fusion reserves, and towards the nose - negative ones.

18.2.1.4. Unfriendly strabismus

Unfriendly strabismus, unlike friendly strabismus, is caused by dysfunction of the extraocular muscles (paresis or paralysis). The causes may be different: traumatic brain or orbital injuries, tumors, congenital, inflammatory or endocrine pathologies.

Paralytic strabismus can be caused by paralysis of one or more extraocular muscles. It is characterized primarily limitation or lack of mobility mowing

eyes in the direction of action of the paralyzed muscle. When looking in this direction, it appears double vision, or diplopia. If with concomitant strabismus a functional scotoma relieves double vision, then with paralytic strabismus another adaptation mechanism arises: the patient turns his head in the direction of the action of the affected muscle, which compensates for its functional insufficiency. Thus, the third symptom characteristic of paralytic strabismus arises - forced turn of the head. So, with abducens nerve palsy (impaired function of the external rectus muscle), for example the right eye, the head will be turned to the right. Forced rotation of the head and tilt towards the right or left shoulder with cyclotropia (displacement of the eye to the right or left of the vertical meridian) is called torticollis. Ocular torticollis should be differentiated from neurogenic, orthopedic (torticollis), and labyrinthine (with otogenic pathology). Forced rotation of the head allows you to passively transfer the image of the object of fixation to the central fovea of the retina, which eliminates double vision and provides binocular vision, although not quite perfect.

A sign of paralytic strabismus is also inequality of primary strabismus angle(squinting eye) secondary deflection angle(healthy eye). If you ask the patient to fix a point (for example, look at the center of the ophthalmoscope) with a squinting eye, the healthy eye will deviate to a much larger angle.

In paralytic strabismus, it is necessary to determine the affected extraocular muscles. In children preschool age this is judged by the degree of eye mobility in different directions (determination of the field of view). At an older age

They use special methods - coordimetry and provoked diplopia.

Simplified method The definition of the field of view is as follows. The patient sits opposite the doctor at a distance of 50-60 cm, the doctor fixes the patient’s head with his left hand and asks him to alternately watch with each eye (the second eye is covered at this time) the movement of an object (pencil, hand ophthalmoscope, etc.) in 8 directions. Muscle deficiency is judged by the limitation of eye mobility in one direction or another. In this case, special tables are used. Using this method, only severe limitations in eye mobility can be identified.

If there is a visible deviation of one eye vertically, a simple method of adduction - abduction. The patient is asked to look at an object, move it to the right and left and observe whether the vertical deviation increases or decreases with extreme gaze aversions. Determination of the affected muscle in this way is also carried out using special tables.

Coordimetry according to Tess is based on dividing the visual fields of the right and left eyes using red and green filters.

To conduct the study, a coordimetric set is used, which includes a graphed screen, red and green flashlights, and red-green glasses. The study is performed in a darkened room, on one of the walls of which there is a screen divided into small squares. The side of each square is equal to three angular degrees. In the central part of the screen there are nine marks placed in the form of a square, the position of which corresponds to the isolated physiological action of the oculomotor muscles.

A patient wearing red-green glasses sits at a distance of 1 m from the screen. To examine the right eye, a red flashlight is placed in his hand (red glass in front of the right eye). The researcher holds a green flashlight in his hands, the beam of light from which he directs one by one to all nine points and asks the patient to combine the light spot from the red flashlight with the green light spot. When trying to combine both light spots, the examinee usually makes a mistake by some amount. The doctor records the position of the green spot to be fixed and the red spot to be trimmed on a diagram (sheet of graph paper), which is a small copy of the screen. During the examination, the patient's head should be motionless.

Based on the results of a coordimetric study of one eye, it is impossible to judge the state of the oculomotor system; it is necessary to compare the results of coordimetry of both eyes.

The field of view in the diagram drawn up based on the results of the study is shortened in the direction of action of the weakened muscle, while at the same time there is a compensatory increase in the field of view in the healthy eye in the direction of the action of the synergist of the affected muscle of the squinting eye.

Method for studying the oculomotor system in conditions of provoked diplopia according to Haab-Lancaster is based on assessing the position in space of images belonging to the fixating and rejected eye. Diplopia is caused by placing a red glass on the squinting eye, which makes it possible to simultaneously determine which of the double images belongs to the right and which to the left eye.

The nine-point study design is similar to that used for coordimetry, but there is one (rather than two).

The study is carried out in a dimly lit room. There is a light source at a distance of 1-2 m from the patient. The patient's head should be motionless.

As with coordimetry, the distance between the red and white images in nine gaze positions is recorded. When interpreting the results, it is necessary to use the rule according to which the distance between double images increases when looking in the direction of the action of the affected muscle. If during coordimetry the field of view is recorded (decreases with paresis), then with “provoked diplopia” the distance between double images is assessed, which increases with paresis.

Surgery - the main type of treatment for non-friendly forms of strabismus.

Often shown plastic surgery. So, with paralysis of the abducens nerve and the absence of outward movements of the eyeball, the fibers of the upper and lower rectus muscles (1/3 - 1/2 the width of the muscle) can be sutured to the external rectus muscle.

Surgical approaches to the oblique muscles, especially the superior oblique, are more difficult, due to the complexity of its anatomical course. Various types of interventions have been proposed on these, as well as vertically acting rectus muscles (superior and inferior rectus). The latter can also be recessed (weakened) or resected (strengthened).

When performing surgery on the extraocular muscles, it is necessary to handle them carefully, without disturbing the natural direction of the muscle plane, especially if this is not clinically justified. Special operations performed for complex types of strabismus can change not only the strength, but also the direction of action

muscles, however, before performing them, it is necessary to conduct a thorough diagnostic study.

One of the methods of treating paralytic strabismus is prismatic correction. More often it helps in the treatment of recent paresis and paralysis of the extraocular muscles in adults, for example after traumatic brain injury. Prismatic glasses combine double images, preventing the patient from developing diplopia and forced head rotation. Medication and physiotherapeutic treatment are also possible.

18.2.2. Nystagmus

Nystagmus is a severe form of oculomotor disorders, manifested in spontaneous oscillatory eye movements and accompanied by a significant decrease in visual acuity - low vision. The development of nystagmus can be caused by the influence of central or local factors.

Nystagmus usually occurs with congenital or early-acquired vision loss due to various eye diseases (optic clouding, optic nerve atrophy, albinism, retinal dystrophy, etc.), resulting in disruption of the mechanism of visual fixation.

With some types of nystagmus, sufficiently high visual acuity is maintained; in such cases, the reason for its development is disturbances in the regulation of the oculomotor system.

Depending on the direction of the oscillatory movements, horizontal (most often observed), vertical, diagonal and rotational nystagmus is distinguished; according to the nature of the movements, pendulum-like (with equal amplitude)

amplitude of oscillatory movements), jerk-like (with different amplitudes of oscillations: the slow phase - in one direction and the fast phase - in the other), mixed (either pendulum-like or jerk-like movements appear). Jerky nystagmus is called left- or right-sided depending on the direction of its fast phase. With jerky nystagmus, there is a forced rotation of the head towards the fast phase. With this rotation, the patient compensates for the weakness of the oculomotor muscles, and the amplitude of the nystagmus decreases, therefore, if the head is turned to the right, the “right” muscles are considered weak: the external rectus of the right eye and the internal rectus of the left eye. This type of nystagmus is called right-sided.

Nystagmus can be large-caliber (with an amplitude of oscillatory eye movements of more than 15 o), medium-caliber (with an amplitude of 15-5 o), small-caliber (with an amplitude of less than 5 o).

To determine the amplitude, frequency and nature of oscillatory nystagmoid movements, an objective research method is used - nystagmography. In the absence of a nystagmograph, the nature of the nystagmus amplitude can be determined by the degree of displacement of the light reflex from the ophthalmoscope on the cornea. If the light reflex during oscillatory movements of the eyes moves from the center of the cornea to the middle of the distance between the center and the edge of the pupil, they speak of small-caliber, small-scale nystagmus, if it goes beyond these limits - large-caliber. If the movements of both eyes are not the same, such nystagmus is called dissociated. It is observed extremely rarely.

When examining patients with nystagmus, the results of electrophysiological studies (electroretinogram, visual

evoked potentials, etc.), allowing you to clarify the diagnosis, determine the degree of organic lesions, the presence of amblyopia and determine treatment tactics.

With nystagmus, the visual acuity of each eye is examined with and without glasses, with the head in a straight and forced position. In this position, the amplitude of the nystagmus usually decreases and visual acuity becomes higher. This criterion is used to decide whether it is advisable to perform surgery on the extraocular muscles. It is important to determine visual acuity with two eyes open (with and without glasses), since with binocular fixation the amplitude of nystagmus also decreases and visual acuity becomes higher.

The system of measures to improve visual functions with nystagmus includes carefully selected optical correction for distance and near. It is also necessary to select special correction tools (magnifying glasses, hyperocular glasses), and use projection magnifiers. With albinism, retinal dystrophy, partial atrophy optic nerves, it is advisable to select protective and visual acuity-enhancing color filters (neutral, yellow, orange, brown) of the density that provides the greatest visual acuity.

With nystagmus, accommodative ability is also impaired and relative amblyopia is noted, so pleoptic treatment and accommodation training exercises are prescribed. Lights through a red filter (on a monobinoscope), selectively stimulating the central zone of the retina, stimulation with contrast-frequency and color test objects (Illusion device, computer exercises according to the programs “Zebra”, “Spider”, “Cross”,

"EYE") These exercises can be performed sequentially for each eye and with both eyes open. Binocular exercises and diploptic treatment (dissociation method, binarimetry) are very useful, also helping to reduce the amplitude of nystagmus and increase visual acuity.

Drug therapy for nystagmus is used to improve nutrition of the tissues of the eye and retina (vasodilators, vitamin complex).

Surgical treatment of nystagmus is performed to reduce oscillatory eye movements. With jerky nystagmus, when a forced rotation of the head is diagnosed with an increase in visual acuity and a decrease in the amplitude of the nystagmus in this position (“rest zone”), the goal of the operation is to move the “rest zone” to the middle position. For

This is done by weakening stronger muscles (on the side of the slow phase) and strengthening by weaker muscles (on the side of the fast phase). As a result, the head position straightens, nystagmus decreases, and visual acuity increases.

Questions for self-control

1.What are the extraocular muscles and cranial nerves provide eye movements?

2. Why does functional scotoma occur?

3.Name the stages of complex treatment of concomitant strabismus.

4.What methods of pleoptic treatment are used for amblyopia?

5.What is diploptics? List its methods.

6. Is it possible to help a patient with nystagmus?

There are only six oculomotor muscles, four of them are straight, two are oblique. The muscles received this name due to the peculiarities of their course in the orbit, as well as their attachment to the apple of the eye. The work of muscles is controlled by three cranial nerves: oculomotor, abducens, trochlear. Each muscle fiber of this muscle group is rich in nerve endings, which provides movements with particular precision and clarity.

Thanks to the oculomotor muscles, variability of movements of the eyeballs is ensured, including unidirectional ones - up, to the right, etc., and multidirectional ones - bringing the eyes together. The essence of such movements is that, due to coordinated muscular work, the same image of an object falls on one area of the retina - the macular area, which ensures good vision and gives a sense of spatial depth.

It is customary to distinguish six oculomotor muscles, four of them go in a forward direction and are called rectus muscles: internal, external, superior, inferior. The remaining two have a slightly oblique direction of movement, as well as a way of attaching the eye to the apple, and therefore are called oblique: upper and lower.

All muscles, excluding the inferior oblique, originate in a dense connective tissue ring that surrounds the external opening in the optic canal. At the very beginning, 5 muscles form a kind of muscular funnel, where the optic nerve, blood vessels and nerves pass. Afterwards, the superior oblique muscle gradually deviates upward and inward, moving towards the so-called block. This is the place where the muscle transforms into a tendon, thrown through the pulley loop, which is why it changes direction to oblique, then attaching in the area of the upper outer quadrant of the eyeball below the superior rectus muscle. The inferior oblique muscle originates from the inferior internal orbital margin, passes below the inferior rectus muscle outward and posteriorly, and is attached in the region of the inferior external quadrant of the eyeball.

In the immediate vicinity of the eyeball, a superficial layer appears on the muscles - a dense capsule of Tenon's membrane. Their attachment to the sclera occurs at different distances from the limbus. The internal rectus muscle is attached especially close to the limbus of the rectus muscles, and the superior rectus muscle is further away from the rest. The oblique muscles are attached to the apple of the eye slightly behind the equator of the eyeball - the middle of its length.

The work of muscles is largely regulated by the oculomotor nerve. It controls the internal, superior, inferior oblique and inferior rectus muscles. The functions of the external rectus muscle are controlled by the abducens nerve, while the superior oblique muscle is controlled by the trochlear nerve. The peculiarity of such nervous regulation is that one branch of the motor nerve controls the work of a very small number muscle fibers, which allows for maximum precision in eye movements.

The movements of the eyeball depend entirely on the characteristics of the muscle attachment. The attachment zone of the external and internal rectus muscles corresponds to horizontal plane eyeball, which provides horizontal movements: turning them towards the nose (contraction of the internal rectus muscle) or towards the temple (contraction of the external rectus muscle).

The inferior and superior rectus muscles provide mainly vertical eye movements, but due to the fact that the line of muscle attachment is localized somewhat obliquely in relation to the limbus line, along with the vertical movement of the eyes, their inward movement also occurs.

The oblique muscles, when contracting, cause more complex movements, this is due to certain features of the location of the muscles, as well as their attachment to the sclera. The function of the superior oblique muscle is to lower the eye and turn it outward, and the function of the inferior oblique muscle is to lift it and move it outward.

At the same time, the superior and inferior rectus muscles and oblique muscles are capable of providing slight rotations of the eye clockwise or counterclockwise. Good nervous regulation, as well as coordinated work of the muscles of the eyeball, make it possible to perform complex movements: unilateral or directed in different directions, which ensures the volume and quality of vision, its binocularity.

Video about the structure of the eye muscles

Diagnostic methods

Visual study of eye mobility, assessing the completeness of movements when tracking a moving object.
Strabometry is an assessment of the angle of deviation of the eye during strabismus from the midline.
A test with alternate covering of the eyes, which determines hidden strabismus - heterophoria, and in the case of obvious strabismus, determines its type.
Ultrasound diagnostics to determine lesions of the oculomotor muscles localized close to the eyeball.
Magnetic resonance imaging, computed tomography - identification of lesions of the oculomotor muscles throughout.

Symptoms of diseases

Double vision - the condition can be caused by obvious strabismus or severe hidden strabismus.
Nystagmus - occurs due to a violation of the ability to fix objects with the gaze.
Impaired conjugal eye movement, limited mobility of the affected eye.
Pain that increases with eye movement.
Drooping eyelid.
Impaired binocular vision.

Diseases affecting the muscles of the eye

Strabismus.
Ptosis.
Muscle inflammation (myositis).
Lagophthalmos.
Blepharospasm.
Heterophoria.
Refractive error (myopia, hypermetropia).

The eye is important sensory organ, which gives us the opportunity to see and enjoy the colors of the world around us, so when eye diseases occur, this causes serious problems in our lives. The functions of the muscles of the eyeball are to rotate both eyes in a coordinated manner, ensuring their coordinated work so that the image is projected onto the same areas retina (macula area) of both organs of vision, providing good vision and a sense of three-dimensional image.

The eye and its motor organs

It consists of the following main parts:

The eye muscles are the organs of the eye., responsible for the ability of the eyeball to turn in the direction of the object in question. They are located in the eye socket and attached to the sclera (the outer layer of the eyeball).

Receiving signals from the brain through the three oculomotor nerves, the muscles of the eye contract, ensuring its rotation in the desired direction.

Distinguish six extraocular muscles:

four straight;
two oblique.

Rectus muscles are called because they move the eyeball in a straight direction, up and down, left and right. Oblique provide turning apple around its axis. Together they enable our organ of vision to perform complex rotational movements.

In turn, the rectus oculi muscles are divided into:

upper;
lower;
internal;
external.

Obliques are divided into:

superior oblique;
lower oblique.

Features of the structure of the system of ocular organs of movement

All extraocular muscles(with the exception of the inferior oblique) are attached to the connecting cartilaginous ring in the upper part of the optic canal in the depths of the lower part of the eye, forming a special structure - muscle funnel, inside which pass the optic nerve and blood vessels supplying the eyeball.

Moving away from the funnel, they approach the sclera of the eye and attach to it. The superior oblique passes into the tendon, which is thrown through the eye block loop and is attached to the eyeball under the inferior straight line. Connection of the muscles of the eyeball with the central nervous system is carried out using several nerves:

oculomotor;
diverting;
lateral.

Oculomotor nerve controls the rectus superior, inferior and internal extraocular muscles, as well as the inferior rectus and inferior oblique. The abducens nerve is responsible for the work of the direct external nerve, and the lateral nerve is responsible for contracting the superior oblique. This division of management functions ensures precision coordination eye movements.

Feature of attachment to the sclera The external and internal muscles give them the ability to turn the eye in a horizontal direction: contraction of the internal straight causes a rotation in the direction of the nose, the external - in the direction of the temporal bone.

Vertical eye movements are ensured by contraction of the straight lines of the lower and upper muscles, but due to the fact that their attachment points are located at an angle to the horizontal axis of the eye, simultaneously with the vertical movement, an inward movement occurs.

The oblique muscles provide quite complex movements of the eye: with the help of the lower oblique - lowering and turning inward, with the upper oblique - raising and turning outward. Well-coordinated teamwork The lateral and oblique muscles allow you to rotate your eyes clockwise and counterclockwise.

Diseases caused by improper functioning of the eye muscles

Violation of the proper functioning of the motor elements of the visual organs can lead to the following diseases:

strabismus – asymmetrical arrangement of the eyes;
paresis - inability of the oculomotor muscles;
nystagmus – involuntary eye vibrations;
myasthenia gravis – muscle weakness;
visual impairment (myopia, farsightedness, astigmatism).

Eye muscle training

One of the means of preventing diseases is training the eye muscles. Muscle training exercises should be performed in conjunction with physical exercise, combined with breathing exercises and relaxation exercises.

To improve vision and prevent eye diseases, many famous ophthalmologists have developed various sets of exercises to strengthen muscles. Among them we can note the system of the American ophthalmologist William Horatio Bates.

As a result of his research, Dr. Bates concluded that the basis of eye diseases and, in particular, poor vision is chronic overstrain of the eye muscles, so his method is based on exercises to relax them. Bates believed that complete relaxation can be achieved through mental relaxation.

Dr. Bates' method is based on the following exercises:

palming;
mental representation;
memory;
visualization;
solarization.
visualization;
solarization.

Palming is relaxation of the eyes covered with the palms of the hands.

Sit comfortably on a chair, relax, straighten your back, keep your head straight, breathe evenly and calmly. Direct your gaze to some object in front of you, looking at it. Then gently close your eyes and place your crossed palms over your eyes so that they lie like the temples of glasses on the bridge of your nose, and place your elbows on the table. Immerse yourself in relaxation and pleasant memories. Then imagine a black screen in front of the gases. The blacker the color you can imagine, the more relaxation you will achieve.

Mental image.

While palming, imagine a color screen in front of you, alternately changing colors: red, orange, yellow, green, blue, indigo, violet. The duration of the presentation of flowers is no more than a second. The duration of the exercise should be 5 – 10 minutes.

Memories.

Batesie believed that during pleasant memories the nervous system relaxes, and along with it our visual organs. Sit comfortably, relax, breathe evenly, close your eyes as if palming and immerse yourself in pleasant memories from your life.

Visualization.

When performing palming, while relaxing, imagine the vision test table as if you can clearly see all the lines.

Solarization.

Batesy believed that the sun is a source of energy for the eyes, and in order for them not to be afraid of the bright sun, they should be exposed to the sun's rays more often. At sunrise or sunset, look at the sun, then close your eyes with your palms, as if palming, so that they absorb the energy of the sun.

The described exercises should be done a little every day, but as often as possible. In his books, Dr. Batesy writes that this technique helped improve vision for many of his patients with myopia, farsightedness, astigmatism and strabismus; by performing his exercises daily, you can get rid of eye ailments.

The eye is a very delicate instrument of vision, which consists of a huge number of elements - blood vessels, nerves and, of course, muscles. The eye muscles, if classified by type, are quite diverse, each of them is responsible for its own area, but at the same time they work in a complex manner.

Anatomy of the eye

The muscles of the eye are usually called oculomotor muscles. There are a total of 6 of them in humans: 4 straight and 2 oblique. They were given such a name for a reason - everything directly depends on their course inside the orbit. In addition, various features of how they are attached to are also taken into account.

Several cranial nerves are responsible for the functioning of the visual muscles:

oculomotor;
abductor;
side.

All muscle fibers are literally filled with nerve endings, which allows their movements and actions to be as coordinated and more accurate as possible. In essence, their work involves the most varied and numerous movements of the eyes. These can be options left-right, up-down, sideways, corners, etc. As a result of such well-established work of the visual muscles, the same images can fall on the same areas of the retina, which allows a person to see significantly better and gives an excellent sense of deeper space.

The structure of such muscles

The muscles of the eye have as their origin a dense connecting ring - it surrounds the hole located inside. The optic nerve, blood vessels and nerves pass through this hole. Depending on how the eye moves, the eye muscles are quite capable of changing direction. Oculomotor muscles - superior, internal, inferior rectus and oblique. Movement of the eyeball is determined in large part by how the eye muscles are attached. The place where the outer and inner straight versions are attached to the horizontal surface of the apple determines its more correct movement in the horizontal direction.

Eye movements in the vertical direction are provided by the inferior and superior oculomotor muscles. But due to the fact that these are attached slightly obliquely, they provide not only up and down movement, but also inward movement.

The oblique muscles of the eye are responsible for more complex movements of the apple. Doctors attribute this to the peculiarities of their location. For example, the superior oblique is responsible for lowering the eye and turning it outward, etc.

Symptoms of disorders

If your eye muscles hurt, you must definitely look for the cause. Violations of eye activity are becoming quite a serious problem.

Moreover, it is enough for only one muscle to fail for a person to feel serious discomfort.

Moreover, if the eye muscles malfunction, in most cases it will be noticeable to the naked eye.

One of these symptoms may be strabismus. Also, when the oculomotor muscles “break down,” a problem may develop with focusing both eyes on one or another object at once.

If you experience problems with your vision, you should immediately consult a doctor.

After all, with age, the eye muscles become less pliable, and it will become almost impossible to correct the situation. As a result, seeing normally will become quite problematic, and by old age you may even go blind.

How is the problem diagnosed?

Today there are many options for diagnosing problems with the eye muscles. The final diagnosis is made based on a visual examination and the completion of a number of fairly simple tasks. An important point is to determine the level of deviation of the eyeball from a symmetrical position.

Often, diagnostic techniques such as ultrasound, computed tomography and magnetic resonance imaging are used for diagnosis. It is these options that allow you to most accurately and clearly determine the nature of existing damage and deviations.

How to train your eyes?

In order for the eyes to function normally, it is necessary to engage in their general strengthening and improvement.

And it’s not that difficult to do. General strengthening activities should become a daily habit. Then your eyes will be healthier.

At home, it is proposed to use a whole range of activities at once, incl. And breathing exercises. This will saturate the tissues with oxygen and significantly improve vision. The exercises must include exercises for training both the external and internal muscles of the eye. So, for example, you can use various rotations of the eyes in certain directions. To train internal options, an excellent solution would be an eye focusing exercise.

Author of the article: Pavel Nazarov

As well as the peculiarities of attachment to the eyeball. Muscle function is controlled by three cranial nerves: oculomotor, abducens and trochlear. All muscle fibers of this muscle group are rich in nerve endings, which ensures special clarity and accuracy of their movements.

The work of the extraocular muscles involves numerous variations of eye movements, both unidirectional (up, down, right, left) and multidirectional (for example, bringing the eyes to the bridge of the nose). The essence of these movements is the coordinated work of the muscles, due to which the same images of objects fall on the same areas - the area. This provides good vision and gives a sense of depth in space.

The structure of the eye muscles

Humans have 6 extraocular muscles. Four rectus muscles have a direct direction of movement: internal, external, inferior and superior. The two oblique muscles of the eye have an oblique direction of movement and a similar attachment to the eyeball (inferior and superior oblique muscles).

The origin of all muscles (excluding the inferior oblique) is a dense connective tissue ring surrounding the external opening of the optic canal. At its very beginning, the five muscles form a muscular funnel, with blood vessels and nerves running inside it. As the movement progresses, the superior oblique muscle gradually deviates inward and upward, following the pulley, in which it passes into a tendon thrown through the loop of the pulley. At this point, it changes its direction to oblique and is attached in the area of the upper outer quadrant of the eyeball, located under the superior rectus muscle. The path of the inferior oblique muscle begins at the lower inner edge of the orbit and continues outward and posteriorly, being under the inferior rectus muscle, where the muscle fibers insert in the lower outer quadrant of the eyeball.

When approaching the eyeball, the muscles appear in a dense capsule - Tenon's membrane, with which they are connected at different distances from the limbus. The inner rectus muscle is the closest to the limbus, followed by the superior rectus muscle. The oblique muscles have a slightly different dislocation; they are attached to the eyeball posterior to the equator, namely in the middle of the length of the eyeball.

The oculomotor nerve is responsible for the work of the superior, internal, inferior rectus and inferior oblique muscles. The work of the external rectus muscle is provided by the abducens nerve, and the superior oblique muscle is provided by the trochlear nerve. The peculiarity of the nervous regulation of the oculomotor muscles is that one branch of the motor nerve is capable of controlling the work of only a small number of muscle fibers, which ensures maximum accuracy of eye movements.

Movements of the eyeball depend, among other things, on the characteristics of muscle attachment. The attachment points of the external and internal rectus muscles are located on the horizontal plane of the eyeball, which makes its horizontal movements possible: turning to the nose - contraction of the internal rectus muscle, turning to the temple - contraction of the external rectus muscle.

The inferior and superior rectus muscles provide vertical movements of the eyes, however, due to the fact that the line of muscle attachment is located slightly obliquely in relation to the limbus, simultaneously with the vertical movement of the eye, inward movement also occurs.

Contraction of the oblique muscles causes quite complex movements, which is due to the peculiarities of their location and attachment to the sclera. Thus, the superior oblique muscle can lower the eye and rotate it outward, while the inferior oblique muscle raises the eye and moves it outward.

Also, the inferior and superior rectus muscles of the eye, together with the oblique muscles, provide slight rotations of the eyes clockwise and counterclockwise. Good nervous regulation and coordinated work of the eye muscles make complex movements possible, thereby ensuring three-dimensional and binocular vision and increasing its quality.

Methods for diagnosing the condition of the extraocular muscles

Determination of eye mobility with assessment of the completeness of movements when tracking a moving object.

Strabometry is an assessment of the degree or angle of deviation from the midline of the eyeball at .

Testing with alternate covering of one and the other eye to determine the hidden form of strabismus - heterophoria, and in case of obvious strabismus, determining its type.

Ultrasound diagnostics – detection of changes in the extraocular muscles in the immediate vicinity of the eyeball.

Magnetic resonance imaging and computed tomography are used to detect changes in the oculomotor muscles throughout.

Symptoms of eye muscle diseases

– occurs with obvious strabismus or pronounced strabismus of a latent form.

– occurs when the eyes’ ability to fix objects is impaired.