Test for self-determination of strabismus. Diagnosis of strabismus and how to determine the type of pathology How to check whether you have strabismus

Strabismus is usually called a deviation of the visual axis due to weakness or improper functioning of the muscles of the visual organs, which are responsible for correctly focusing the pupil on an object.

This disease can leave consequences, so any parent will be interested in how to determine strabismus in a child and the ability to do it themselves at home.

For such purposes, there are indeed several tests that can be carried out with children, but none of the tests will show a 100% result that the child has strabismus, because high-quality diagnostics should be carried out exclusively in specialized institutions under the supervision of experienced doctors.

Strabismus in children

How to determine strabismus in a child? Source: glavvrach.com

Another common visual disorder in children is strabismus. However, strabismus itself is extremely rarely an independent disorder. Most often, strabismus is a concomitant phenomenon of diseases such as astigmatism and farsightedness.

And in especially severe cases, divergent strabismus in children is a consequence of myopia. Parents should remember that children's strabismus is not just some kind of cosmetic defect, but a severe disruption of the functioning of the entire visual apparatus.

Normally, the human visual system has a structure in which two different images from the two eyes enter through the visual channels into certain areas of the brain, where they are reunited into a single whole.

And only with the correct, well-coordinated work of the entire visual apparatus, the picture acquires the correct clear outlines, thanks to which a person sees objects from the correct angle, and it is also possible to adequately navigate in space.

A baby who has just come into our world is still, in principle, unable to look and see clear objects. The ability to see with both eyes (binocular vision) develops gradually in a child, finally becoming fully formed only by the age of 4–5 years.

I would like to remind you that at this age all children are also susceptible to physiological myopia, which is directly related to the development of strabismus. Therefore, treatment must be exclusively comprehensive - only in this case is it possible to achieve positive dynamics.

Most often, strabismus is diagnosed in children aged three to five years, however, strabismus in infants is quite common. As a rule, the first to notice symptoms of trouble are parents of children, who spend all their free time with their children.

Many parents ask how to determine strabismus in a child. In fact, if a child does develop strabismus, you will immediately notice it with the naked eye, even without special education.

And if you notice that your child is squinting even a little, rush to seek help from a pediatrician - an ophthalmologist for advice as soon as possible.

You should not be afraid that you will bother the doctor in vain - when it comes to the child’s health, it is much better to be safe than to miss the onset of any disease. Not a single doctor will refuse to help you or blame you.

After all, only an ophthalmologist knows how to treat strabismus in children. Correcting strabismus in children is a labor-intensive process and requires a lot of effort, both from the doctor and from the parents.

Classification

Ophthalmologists offer several classification options for this type of disease. The most common is the division into three main subtypes: imaginary strabismus, esotropia and exotropia.

Imaginary strabismus

It is observed in children under one year of age. It is characterized by the anatomical feature of the eyelids, the presence of skin folds in the peripheral zone of the cornea of the eye with a relatively wide bridge of the nose. The fold covers some area of the eye, and a visual effect is created from the side as if the baby’s eyes are looking in different directions.

With age, the child “outgrows” this anatomical defect and not a trace remains of strobism. That is, if a specialist determines that a child has imaginary strabismus, then parents should have no reason to worry, this is not a disease.

Esotropia

The pupil deviates towards the nose. There are two subtypes of esotropia: congenital and accommodative.

Congenital esotropia is a pronounced heterotopia, caused by a genetic predisposition. Identified in babies aged 0 to 6 months. A peculiarity of this type is that during periods of deterioration in health or during times of fatigue, the child experiences an increase in the effect of a squinted gaze.
Accommodative esotropia, detected in children aged eight months to four years, is usually a concomitant disease - childhood ametropia (farsightedness). A child, when examining an object at close range, strains the muscles of the eye, and a deviation occurs. It is at these moments that strabismus most clearly manifests itself. That is, there is a direct relationship: the more often the child examines small objects at close range, the better the disease is expressed. The dynamics of this type of strabismus are varied, from rapid deterioration to a relatively low rate of development.

Exotropia

The eye deviates towards the temple. As a rule, this type of strabismus begins to appear in children aged one year. It may be temporary or permanent. Unlike the previous case, it occurs when the patient peers into the distance for a long time, but when examining objects close up, it is either barely noticeable or disappears altogether. In this case, the child may experience headaches, the object of observation may split in two, and tearing appears.

Is strabismus always noticeable with the naked eye?

Strabismus can be vertical, divergent and convergent, most often with one or both eyes clearly squinting. However, there is also a hidden form of childhood strabismus, which is not outwardly noticeable. It occurs due to muscle imbalance and is dangerous because it causes rapid eye fatigue.

This, in turn, leads to myopia. The disorder develops in the first months of life, and can manifest itself more clearly in the third year of life, when the child is interested in activities that require visual strain - modeling, drawing.

Sometimes strabismus is observed in newborns. This is due to weakness of the eye muscles and is normal. The reason for contacting an ophthalmologist is the presence of obvious strabismus in a child older than six months.

What should you pay attention to first?

Recently, more and more often, ophthalmologists have to diagnose various visual impairments. Very often, doctors diagnose strabismus in children under one year of age.

This is influenced by a huge number of different factors, including the environmental situation, computers and televisions, which have become firmly established in the life of a modern person, complications during the mother’s pregnancy, and many others.

The factor of genetic predisposition is also important - vision problems often tend to be passed on from generation to generation, from children to parents.

If the baby’s parents have any vision problems, be it myopia, farsightedness, astigmatism or strabismus, there is a fairly serious risk that their child will also have a tendency to the same diseases.

That is why parents with vision problems should treat their baby’s vision as carefully as possible. After the baby reaches three months of age, parents should definitely go to an ophthalmologist to get the first consultation in the baby’s life.

Most often, a referral to an ophthalmologist is given by the pediatrician who is observing the baby. However, if for some reason your pediatrician did not give you a referral to an ophthalmologist, do not hesitate to remind him about it yourself.

An ophthalmologist will carefully examine your baby and conduct the necessary examination, which will help the doctor identify possible visual impairments. If the baby has any problems, the doctor will tell the parents what needs to be done next.

And if the child needs treatment, it is the ophthalmologist who will write out the treatment regimen or refer him for hospitalization to a specialized hospital. If no one in your family has had any problems with vision, the baby’s first visit to the ophthalmologist should be at six months.

After this, if the ophthalmologist does not detect any violations, the next visits will take place as planned, during preventive examinations of the child. In no case, if the doctor says that the child’s vision is fine, do not ignore subsequent visits.

As you know, not all vision problems are congenital - many eye diseases are acquired over time, under the influence of a huge number of adverse effects on the baby’s eyes.

You should also draw the attention of parents to the fact that in no case should you completely rely only on doctors. Firstly, you won't visit an ophthalmologist every week, will you?

And secondly, individual symptoms of some diseases can only be noticed by parents who spend almost all the time with their child. Therefore, mothers and fathers must be extremely attentive and watch the baby.

Ophthalmologists, as a rule, tell parents about which aspects of children's vision they need to pay special attention to. Below we have described the main ones - read carefully and try to remember this information. So:

The baby's reaction is not bright

Almost all young mothers have more than once observed the following picture: the light turns on in the child’s room, and the child immediately reacts to this - he turns his head away, closes his eyes and shows other signs of dissatisfaction. This reaction is the physiological norm.

By closing his eyes, the child thus instinctively protects his eyes, helping them adapt to bright light. But if the baby does not react in any way to bright lighting, especially to a light suddenly turned on in a dark room, parents need to be wary.

In this case, there are two acceptable explanations: either you are lucky and you are the parents of an unrealistically calm child, or, what is more likely, your baby has certain vision problems.

To find out if this is so, try to casually direct a beam of light directly into the baby’s eyes and hold it for 1 - 2 seconds. Never let sunbeams into your baby's eyes - this can damage the retina.

If in this case the baby does not react in any way to the bright light, parents should seek help from an ophthalmologist as soon as possible and show the child to him. The doctor will examine the child and accurately diagnose or, on the contrary, dispel your fears and concerns.

Recognizing your toys

Pay attention to whether your baby can independently find his toys - rattles, balls, dolls. If the child’s vision is fine, he will recognize his toys even from a distance. Moreover, the child should see them equally well with both eyes - both right and left.

If your child is old enough, you can try to test your vision yourself - show him an object and ask him to name it. After that, move on to smaller details - for example, ask to tell what color the wheel of the car is or find out if there is a pocket on the doll's skirt.

But even if the baby is not yet big enough and cannot yet maintain a dialogue, attentive parents are able to notice that not everything is in order with the baby’s vision.

For example, some parents whose children suffer from eye diseases say that a situation very often occurs when the child persistently reaches out to an object that interests him. But as soon as you give him the object, the baby throws it and may even cry.

This happens because the baby is disappointed, since the item turned out to be not at all what the baby wanted to receive. If this periodically happens to your baby, be sure to consult an ophthalmologist.

Squinting your eyes

Have you noticed that sometimes, when looking at some objects that are at a great distance from the child, your baby begins to squint his eyes?

Try asking him a few leading questions that will allow you to understand whether the child sees these objects. If the child cannot answer these questions, or complains that he sees poorly, take this into account and show the child to an ophthalmologist as soon as possible.

Assessing the location of various objects

A very important factor in good vision is the child’s ability to follow a moving object with his eyes without losing it from his field of vision. Even very small babies discover this skill by following their mother, a rattle or a mobile phone with their eyes. If your baby fails to do this, show him to the doctors.

Moreover, please note that you need to consult not only an ophthalmologist, but also a neurologist, since the child’s inability to follow objects with his eyes may also indicate the presence of disturbances in the normal functioning of the central nervous system.

Red eyes, watery eyes

If the child's eyes periodically look inflamed and red, pay attention to whether the child's eyes are overloaded - perhaps he spends too much time in front of the TV or at the computer? Or maybe he cried recently?

If the eyes turn red periodically, and for no apparent reason, this is also an alarm signal for parents - be sure to consult an ophthalmologist, who will help determine the cause of regular eye inflammation.

Causes of the disease

Microphthalmos (shrinkage of the eyeball);
corneal opacities;
cataract (clouding of the lens);
iris coloboma (congenital absence of part of the eye shell);
uveitis (disease of the uvea);
above average astigmatism (impaired shape of the lens or cornea), myopia and farsightedness;
dysarthria or paresis (partial disconnection of muscles from the nervous system);
paralysis;
traumatic brain injury;
infectious disease (influenza, diphtheria, scarlet fever, measles, etc.);
abnormal development of the eye muscles and other eye diseases;
stress;
severe fear;
somatic diseases (asthenia, neuroses, affective disorders, etc.).

Can strabismus be inherited?

If one of the parents or one of the child’s immediate relatives suffers from strabismus (heterotropia), then there is a possibility that the child will develop this disease. That is why children prone to developing strabismus need to be regularly observed by a pediatric ophthalmologist for timely detection of pathology.

This is because some vision defects, such as abnormalities of the eye muscles or improper attachment of the eye muscles, can be inherited.

What are the causes of strabismus in children?

The causes of strabismus in children can be different - genetic, a consequence of birth trauma or even mental disorders. We will look at the main ones. In addition to genetic factors, the most common cause of strabismus in a child is pathology of pregnancy and childbirth.

Due to fetal hypoxia, as well as due to birth trauma to the cervical spine or brain, innervation is disrupted and the extraocular muscles are deviated from the visual axis. At the same time, myopia, farsightedness and astigmatism can provoke the development of strabismus in a child.

Head injuries, eye surgeries, mental disorders and brain diseases can also cause strabismus in children. There are cases when this pathology occurs in a child after he has had the flu, measles, diphtheria or scarlet fever.

Apparent strabismus

Often, when parents go to the doctor, they complain about their child’s strabismus, but after examination the doctor does not detect it. This happens, as a rule, due to the congenital epicanthus, the structure of the skull or the wide bridge of the nose.

Apparent strabismus is more likely to disappear with age as soon as the skeleton begins to change. To determine hidden strabismus, you can try a cover test.

In this case, when the child has both eyes open, strabismus is not observed, but as soon as one of them is closed, the other begins to move to the side, and when opened, returns to its place. The main condition for this method is this: the child must look at the object that is being shown to him.

At 3 years of age, in addition to the above methods, visual acuity is tested using a table with or without glass correction. The state of binocular vision can be determined using a color test.

Color test technique

The study is carried out using a special disk with luminous circles of different colors located on it (1 red, 1 white and 2 green). The child wears glasses specially designed for this purpose with red glass on the right and green on the left.

Thus, the eyes see the color that is in front of them, that is, the right one is red and the left one is green. The white ball appears as one of two colors due to the filters placed in front of the eyes.

If the baby does not have any visual impairments, he will see 4 circles (either 2 red and 2 green, or red and 3 green). If one eye of a child turns off, he sees 3 green or 2 red circles (monocular vision). If the baby has alternating strabismus, he will see either 3 green or 2 red.

How to determine strabismus in a child at home?

Source: zdorovyeglaza.ru

The most effective way to determine all visual impairments is an ophthalmological examination, but strabismus can be detected at home. To do this you will need a flashlight and a camera with flash.

Watch your child. Children with strabismus find it difficult to focus their gaze on a specific object; they often rub their eyes and tilt their heads to the side.
Shine a flashlight into your eyes and watch the reflection in them. If it is the same in both pupils, everything is normal, if it is different, there is strabismus.
Flash photography can also help identify strabismus. Look at the glare from the flash in the child's eyes in the resulting photo.

Home diagnostic method

Of course, congenital strabismus is diagnosed already in the first days of our birth. But with acquired things the situation is different: small deviations are not always noticeable immediately, and medical examinations are not so frequent.

And I would like to determine the tendency to strabismus before visible symptoms appear: deviations of one or both eyes towards the nose or to the side, as well as “floating eyes” syndrome (when it is difficult to “catch” the patient’s gaze).

You can take a test for signs of hidden strabismus (or ask your child to do it) now, it only takes a few minutes.

Rules for performing the test

Lean back in a chair so that your head does not move and look out the window at some small immovable object (for example, a store sign or a satellite dish) and try to focus your gaze on this object for two seconds.

Then close your palm, first one, then the other eye, looking at the object for 1-2 minutes. If the object of fixation remains in place and does not jump from side to side when you open each eye, you can be calm.

Well, or almost calm... After all, only modern diagnostic equipment and professional examination can give a 100% result.

Self-check procedure

In order to independently test for heterotropy at home, it is enough to sit comfortably in a chair, resting your head on the back so that it does not roll when relaxing.

Having sat comfortably, you need to focus your gaze on a static, distant object with high contrast. This could be a bright sign, inscription, etc.

Focusing on the selected object, you need to cover each eye in turn with your palm for a couple of seconds. Breaks should be no longer than 3 seconds of gaze by both organs of visual perception. You cannot let your hand touch your face.

In such conditions, if performed correctly, the object will be seen as if through a phantom palm. In healthy people, a similar phenomenon occurs due to binocular vision, which is impossible with strabismus.

Features of an unhealthy reaction to the test

People with heterotropia have a special reaction to this test, which has the following manifestations:

If, during such a kind of verification test, the object is not in one position, but there is a deceptive feeling that it is moving or slightly deviating when moving the palm, this is evidence of the presence of hidden horizontal strabismus.
When the left eye is closed, you will likely notice a shift of the image to the right, and when the right eye is closed and the left one is open, the effect will be the opposite. This means that you have hidden convergent strabismus.
If, when the left organ of vision is open, the picture shifts to the right, and the right one to the left, then this is a hidden divergent strabismus.
If a static object on which the gaze is focused during the test shifts in different directions, then this indicates the presence of a vertical deviation.

How to determine strabismus in a newborn and one-year-old child?

By the end of the first week of a baby’s life, you can independently diagnose the pathology in question. To do this, you need to take a rattle and remove it from the child’s eyes at different distances, moving it from side to side.

Carefully monitor the reaction of the child's eyes when observing a moving object and draw a conclusion about how mobile the baby's pupils are. In newborns, the gaze may be discoordinated until 3-4 months; after this age, both eyes become aligned.

In some cases, in children with a wide bridge of the nose, strabismus may be apparent. You should consult a doctor and sound the alarm only if, after 4 months of life, the child’s eyes do not look at the same point most of the time.

Strabismus in one-year-old children can be recognized by the following signs:

the child cannot direct his eyes simultaneously to one point in space;
eyes do not move together;
one eye squints or closes in bright sun;
the child tilts or turns his head to look at the object;
the baby bumps into objects (squint impairs the perception of depth in space).

Let us recall once again that true strabismus is characterized by the deviation of only one eye from the joint point of fixation. At the same time, for a newborn child, a slight defocus of the eyes is considered a completely normal phenomenon, which is observed in all babies.

Moreover, the absence of slight strabismus in a small child is rather an exception to the rule. Firstly, the eye muscles of children are very weak, so they need training. Secondly, the child has not yet learned to use these muscles, so sometimes it is not possible to look in different directions.

That is why small eyes, not listening to their owner, either converge to the bridge of the nose, or scatter in different directions. As soon as the baby learns to control the movements of his eyeballs, the squint will go away.

This pathology in infants is inextricably linked with weakness of the eye muscle. The most common causes of strabismus in newborns are:

injuries and infectious diseases of the brain;
changes in the eye muscles of an inflammatory, vascular and tumor nature;
untimely treatment of myopia, astigmatism, farsightedness;
congenital diseases and birth injuries;
increased physical and mental stress;
placing children's toys too close to the baby's face.

Heredity also quite often causes the development of strabismus in newborns. If one of the parents has this pathology, then there is a high probability that their child will inherit the disease.

Sometimes strabismus manifests itself as a symptom of other congenital diseases or as a result of illnesses suffered by the baby’s mother during pregnancy.

Medical definition of strabismus

An ophthalmologist determines the presence of strabismus based on the following examinations:

An examination by an ophthalmologist will help you most accurately determine visual impairment.
Checking visual acuity.
Determination of range of motion, squint angle, eye position.
Examination of the conducting media of the eyes, the anterior segment.
Refraction of the eyes in a child with narrow and wide pupils.
Study of binocular vision.

Strabismus can be completely cured in 2-3 years. At the same time, it is good to combine medical recommendations with special gymnastics for the eyes. Do not delay your visit to the doctor, since children suffering from strabismus often develop disorders of the nervous system and psychological problems.

Ways to get rid of the disease

Medication alone cannot cure strabismus, however, they can speed up the healing process. These include drops to improve vision, drugs that relax the muscles of the eye and prevent pupillary constriction.

And the main methods of treating strabismus include non-hardware procedures (sets of exercises, glasses and lenses), hardware treatment and surgery. Acquired strabismus in adults is more difficult to correct, since their vision has already been fully developed.

In such cases, often with the help of optical methods, a new model of stereoscopic vision is formed (that is, with the help of lenses a person sees better, but the problem is not solved).

Surgical intervention is necessary in cases where a person is not content with a partial improvement in appearance: after all, the surgeon will not restore binocular vision, but he can “put the eyes back in place” by removing or weakening the eye muscles.

And only modern hardware procedures can “teach” the eyes to see correctly. Here are some popular hardware techniques that your doctor may suggest to eliminate strabismus.

Treatment

The easiest way to determine strabismus is to undergo an ophthalmological examination by specialists. Congenital pathology is diagnosed in the first days after birth. The acquired form is not always noticeable; at first it is characterized by slight deviations. There are methods by which you can independently understand whether there is a predisposition to the disease.

Causes and symptoms

Strabismus can be either congenital or acquired. Pathology develops due to the following conditions:

microphthalmos;
cataract;
astigmatism;
coloboma of the iris;
uveitis;
improper development of eye muscles;
fright;
paralysis;
some infectious diseases (scarlet fever, influenza, measles);
traumatic brain injuries;
somatic diseases such as asthenia and neurosis;
stress.

Acquired strabismus is manifested by clinical symptoms such as decreased quality of vision and double vision.

Symptoms of acquired strabismus include:

sharp deterioration in visual functions;
double vision;
drying out of organs;
eye pain;
hemorrhages.

To diagnose strabismus, sometimes not only ophthalmologists are involved, but also neurosurgeons, neuropathologists, and other specialists.

Determination methods

Since the disease is difficult to notice in the early stages, it is important to know how to check your susceptibility to this disease before visible symptoms appear. Congenital pathology is diagnosed by doctors immediately after the birth of the child. The type, type and severity of the acquired form of the disease in adults is determined only by a specialist - an ophthalmologist.

Screening - test at home

To determine strabismus at home, you need to place a chair at home, not far from the window, and sit down so that your head is pressed tightly against the backrest, since it must be motionless during the test. The ideal option would be an office chair; it is convenient to move around the room and can be placed in any place at the desired distance.

Diagnosis of strabismus at a distance

Determination of pathology when looking into the distance can be done at home, looking through glass at a stationary object.

To identify pathology when looking into the distance through a window glass, a contrasting real object is selected, for example, a store sign. Vision is focused on this object, after which, alternately with the hand, without touching the face, one eye is covered for 2-3 seconds, then the other. Diagnostics are carried out for 1-3 minutes so as not to look with both eyes at the same time. If the exercise is performed correctly, people with good vision will see an object through a transparent palm standing next to an opaque one. If the subject of observation jumps to the left or right due to the opening of the eye, then the patient has a horizontal type of strabismus. However, the observed object can move up and down. In this case, the observed pathology is an infrequently encountered vertical type.

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Description

Determining the state of the oculomotor system involves studying both sensory (sensitive) and motor (motor) functions.

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

When studying motor functions determine the mobility of the eyeballs, the amount of deviation, the degree of damage to the functions of various oculomotor muscles.

When collecting anamnesis it is necessary to find out the age of onset of strabismus, its presumed cause, the presence of previous injuries, 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.

Visual acuity testing should be carried out with and without glasses, as well as with two eyes open, which is especially important for nystagmus.

In addition to a general ophthalmological examination, special studies are carried out.

To determine the nature of strabismus (monolateral, alternating) cover the fixating (for example, right) eye of the subject with their palm and ask him to look at the end of a pencil or ophthalmoscope handle. When the deviated eye (left) begins to fixate, remove the palm and leave the right eye open. If the left eye continues to fixate, then the subject has alternating strabismus, but if with two eyes open the left eye squints again - monolateral strabismus. The type of strabismus and the amount of deviation (squint angle) are determined by the direction of the eye deviation (convergent, divergent, vertical).

The strabismus angle is not a stable value, and its exact determination is not required.

For practical purposes, the Hirshberg method is convenient. In this case, the patient looks, for example, into the hole of a hand-held ophthalmoscope, and the doctor, applying the ophthalmoscope to his eye, observes the position of light reflexes on the corneas of both eyes. The size 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 of the iris and limbus (Fig. 3.6).?

Eye mobility is determined when moving a fixation object, which is followed by the patient's eyes, in 8 blinker directions: right, left, up, down, up-right, up-left, down-right, down-left. With concomitant strabismus, the eyes move in a fairly full range. In case of paralytic strabismus, it is advisable to use special methods - coordimetry and provoked diplopia, which allow identifying the affected muscle.

In the presence of vertical deviation, a method is used to determine the angle of strabismus in the lateral positions - adduction and abduction. An increase in the angle of vertical strabismus in adduction indicates damage to the oblique muscles, and in abduction indicates damage to the rectus muscles of the vertical action.

If amblyopia is present, determine state of visual fixation. The study is carried out using one of the main instruments used for strabismus - a cop (Fig. 3.7).

The device is designed like a stationary Gulstrand ophthalmoscope, which allows an eye examination to determine the state of visual fixation when the head is fixed. The child looks at the end of the fixation rod (“needle”) of the monobinoscope, the shadow of which on the fundus of the eye is projected onto the fixation site.

Methods for studying binocular functions in strabismus are based on the principle of separation of visual fields (haploscopy). This makes it possible to identify the participation (or non-participation) of the squinting eye in binocular vision. Haploscopy can be mechanical, color, polaroid, raster, phase (in time), etc.

One of the main haploscopic devices is the synoptophore (Fig. 3.8).

The division of the visual fields of the right and left eyes is carried out mechanically in this device, using two separate ones for each eye on the side, in each of which the subject is presented with paired test objects for combination and merging (Fig. 3.9).

Test objects of the synoptophore can be mixed (horizontally, vertically, torsionally, i.e. when tilted to the sides) and installed in accordance with the angle of strabismus (objective angle). They differ in the control elements for each eye, which makes it possible, when combining these paired patterns, to judge the presence or absence of binocular fusion, i.e. bifoveal physis. If the fusion angle (subjective angle) is not equal to the strabismus angle (objective angle), we speak of nonfoveal fusion. When a detail or the entire pattern disappears in front of the squinting eye, they speak of a functional scotoma, determine its size (regional, total scotoma) and localization (see Table 3.1).

For fusion or scotoma in the nonfoveal area at a subjective angle equal to zero (types 4a and 3a, respectively), there is normal correspondence of retinas of the harmonic type according to the classification of S. Adam (1906), i.e. asymmetric binocular vision (a tendency towards it in type 3), accompanied by the presence of “binocular vision” in free space (color test, Bagoli test) and microdeviation (squint with a small angle).

For types 4b and 3b. previously called “non-harmonic” correspondence, the inherent difference between the magnitude of the objective and subjective angle is due only to different conditions for their determination: the objective angle - with alternating vision with the right and then the left eye, which increases the angle of strabismus, and the subjective angle - with fixation with both eyes, which reduces the angle of strabismus. This situation occurs only with muscle imbalances prone to heterophoria; the effectiveness of treatment of patients with types and approaches the effectiveness of treatment of patients with types 1, 2a, b (regional or total scotoma).

In the presence of bifoveal fusion measure fusion reserves by bringing together or spreading test objects (optical heads of the synoptophore) to the point of their doubling in the horizontal plane when determining positive and negative reserves (convergence and divergence reserves), in the vertical plane (supra- and infrafusion reserves), in the frontal plane ( in- and excycloreserves).

Positive fusion reserves have the greatest value. On the synoptophore on the test 2 (“cats”) they make up 16 ± 8° , negative - 5 ±2° , vertical - - 4-6 prism diopters (2-3°); incycloreserves are in healthy individuals 14 excycloreserves -12 ± 2° .

Fusion reserves depend on the research conditions (using different methods: synoptophore or prism), the size of the tests, their vertical or horizontal orientation and other factors that are used in 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), filters with vertically and horizontally oriented axes, raster filters of mutually perpendicular orientation for both eyes.

These methods make it possible to answer the question of whether the patient has binocular, simultaneous (diplopia) or monocular

Color haploscopy method implemented in a four-point color test. Its prototype was a device created by the English researcher G. Worth (1905) (abroad this method is known as Worth-test).

The device is distinguished by the presence of two green (or blue), one red and one colorless (common test for both eyes) circles. The subject looks through red-green glasses, in which there is a red filter in front of the right eye and a green (or blue) one in front of the left eye. With monocular vision of the right eye, the subject sees through the red glass only red circles (there are two of them); with monocular vision of the left eye, only green ones; with (Fig. 3.10, a, b) simultaneous vision, the subject sees five circles; two red and three green (Fig. 3.10, c). With binocular vision, the subject sees four circles: two red and two green (Fig. 3.10, d, e).

The middle circle can be green, red or mixed depending on the presence of a dominant eye.

Monocular vision on color test can be observed in patients with preserved bifoveal fusion on the synoptophore, as well as in patients with functional scotoma. Therefore, to correctly assess the binocular status of a patient with strabismus, a comprehensive examination is necessary using the listed methods of mechanical and color haploscopy. This allows you to correctly determine the tactics and choose the method of treatment.

When using polaroid and raster filters (the so-called Bagolini glasses), there is also a common object to merge and objects visible only to the right or only to the left eye (Fig. 3.11 and 3.12).

Clinical classification of binocular functions in natural and similar conditions is presented in Table. 3.2.

Methods for studying binocular vision differ in the degree of uncoupling (dissociating) action , more pronounced in the color test, less pronounced in the Polaroid test and in raster glasses. When using the latter, the surrounding space is visible, as in natural conditions (unlike vision with color glasses), and the dissociating effect of the rasters is manifested only by thin, mutually perpendicular light strips passing through the common round object of fixation. Therefore, when examined using different methods, the same patient can be diagnosed with simultaneous vision using a four-point color test and binocular vision using raster glasses. This must be remembered when assessing binocular status to determine treatment tactics.

There are various depth-measuring devices and stereoscopes that allow you to determine the acuity of depth and stereoscopic vision, their thresholds (in degrees or linear quantities). Firstly, the subject must correctly position the real tests presented and mixed in depth, and secondly, determine the depth placement of the tests using two shifted stereopairs. The degree of error determines the acuity of stereo vision.

Divergent concomitant strabismus in sensory status is a more favorable form of the disease, less often accompanied by amblyopia.

With divergent strabismus bifoveal fusion is often preserved; the main disorders are expressed in insufficiency of convergence and accommodative ability (especially the mechanism of relative accommodation).

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Heterotropia or strabismus, which is better known in everyday life as strabismus, is a pathology characterized by deviation of the eye from the central axis. In this case, the eye does not focus on a certain point, and it begins to look to the side.

This disease is considered to be a childhood disease, but it also appears in adulthood. Moreover, it will be much more difficult to cure it than in a child. Therefore, it is necessary to know how to identify strabismus in order to take action in the first stages and begin treatment.

Strabismus or strabismus is a pathology characterized by deviation of the eye from the central axis.

At the age of 3 years, a child undergoes the process of developing friendly eye function. It provides binocular vision and the ability to correctly determine the location of things relative to each other in space. If at this age one or both eyes are squinting, you should consult a doctor and undergo a squint test.

The reasons explaining why this pathology develops are:

disturbance of accommodation due to congenital myopia, farsightedness or astigmatism;
deficiency of vitamins and minerals that appears at an early age;
inflammatory changes in the eye muscles;
pathologies (meningitis, tumors, strokes) or brain damage;
eyeball injuries;
non-compliance with eye stress according to age;
physical or psychological stress.

Classification of strabismus

There are various divisions of the disease into groups depending on the timing of occurrence, the degree of manifestation and the cause of the pathology.

According to the degree of severity, the following are distinguished:

hidden - the angle of strabismus is not visually determined, and the pathology can only be diagnosed with the help of special equipment;
obvious - when the deviation of the eye from the central axis is determined with the naked eye without testing.

Hidden strabismus or heterophoria can only be diagnosed by an ophthalmologist, creating conditions to exclude binocular vision.

By time of problem occurrence:

congenital - from birth, due to the presence of various pathologies, the child has impaired accommodation and does not develop binocular vision;
acquired – the disease can appear in adulthood as a consequence of injury (pathology) to the brain or eye apparatus.

Strabismus is also divided depending on the direction of deviation of the eye from the central point of fixation. Stand out:

convergent - when there is a deviation towards the nose, as a result of which it is combined with hypermetropia;
divergent - there is a shift to the temple and is combined with myopia;
vertical - when one eye squints down or up.

Hidden strabismus can only be diagnosed by a specialist.

There is a division of pathology according to etiology. Here are the differences:

Friendly - alternately squint the eyes at approximately the same angle of deviation. This type is caused by disturbances in accommodative work, which are inherited.
Paralytic – caused by paralysis or injury to the extraocular muscles. In this case, only the healthy eye squints, while the damaged one remains motionless.

Symptoms of the disease

Strabismus may not always manifest itself as a visually noticeable deviation of 1 eye from the axis. And at first, the problem may not make itself felt, developing in a hidden form. And then treatment of the pathology will be more problematic than if the disease is diagnosed in the early stages.

Therefore, it is important to know the main symptoms that indicate problems with the oculomotor system:

headache;
disturbance in the child’s perception of the surrounding world;
dizziness;
visual acuity of the problematic eye worsens;
double vision appears;
instead of a three-dimensional one, a flat image appears;
Amblyopia may appear - characterized by a sharp deterioration of vision in the problem eye, which is caused by a lack of visual load on the eye muscles.

Diagnostics

The final diagnosis can be made by a doctor only after passing special tests and determining the cause of strabismus. For this purpose, the following research methods are used:

the subjective Sivtsev-Golovin table allows you to determine visual acuity in normal condition and with correction;
Binocular vision is studied using the four-point color test;
refraction is determined using skiascopy and a refractometer;
the angle of strabismus is determined;
The friendly functioning of both eyes is assessed using special mirrors.

Treatment

To prevent serious complications such as amblyopia, strabismus should be started early. This is a lengthy process that can take up to several years. To achieve a positive trend, it is important to carefully follow all instructions and regularly see your doctor.

Treatment of concomitant strabismus begins with the correction of accommodation disorders. For this purpose, the preferred correction of astigmatism, myopia or hypermetropia is selected. You may be prescribed glasses, contact lenses, or laser vision restoration. Correction of visual impairment is prescribed from a very early age of the child (from 6 months) and is used until the symptoms of strabismus decrease.

The following treatment methods are aimed at increasing visual acuity, as well as fixing the direction of the eye relative to the central axis. To do this, exercises are used, the purpose of which is to create a visual load for the weakened muscles of the squinting eye.

If you want to achieve a positive trend, it is important to carefully follow all instructions and regularly see your doctor.

If conservative treatment methods do not bring a positive trend, or in the case of paralytic strabismus, doctors may prescribe a surgical operation, during which the tendon muscle is lengthened or shortened using incisions.

Strabismus is a disease that requires prompt and long-term treatment. Therefore, properly selected therapy, compliance with all instructions and preventive measures will help to avoid serious vision problems in the future.

Dec 30, 2016 Doc