- Strabismus: description
- Latent strabismus - Heterophoria
- Strabismus: symptoms
- Strabismus: causes and risk factors
- Strabismus: examinations and diagnosis
- Strabismus: treatment
- Strabismus: Disease course and prognosis
Especially in childhood can squint, in technical language strabismus called, which significantly influence brain maturation and thus severely limit the ability to see for life. Strabismus is when both visual axes diverge when a particular object is focused. Strabismus can have different causes and therefore often requires an individually selected therapy. Read more about strabismus here.
ICD codes for this disease: ICD codes are internationally valid medical diagnosis codes. They are found e.g. in doctor's letters or on incapacity certificates. H50H49
Dr. med. Mira Seidel
From the 6th month of life, the baby should be examined by the ophthalmologist for the first time so that impaired vision, so-called amblyopia, can be detected early.
Latent strabismus - Heterophoria
Causes and risk factors
Examinations and diagnosis
Disease course and prognosis
Normally the eyes are always moved together in the same direction, thus ensuring that a three-dimensional image is created in the brain. However, this balance can be disturbed, so that the visual axes diverge, although actually focused on something.
This strabismus, colloquially referred to as strabismus, is divided into manifest (heterotropic) or latent strabismus (heterophoria). In addition, a distinction is made clinically different shifts, depending on how the visual axis shifts:
- Strabismus convergence (esotropia): Visual axis deviates inwards (inner squint).
- Strabismus divergens (exotropia): Visual axis deviates outwards (outer squint).
- Strabismus verticalis
- hypertrophy: One eye is higher than the other (Höhenschielen).
- hypotropia: One eye is higher or lower (downwards).
- cyclotropia: The eye "rolls" around the visual axis (is very rare).
Squinting in children
Squinting in children is particularly common: Approximately three percent of all children suffer from accompanying squint at some point in their childhood, and in over half of the cases before reaching the age of three. Since the brain of children is still developing strongly, the brain recognizes the false image information of the cross-eyed eye as defective and suppresses this information. As a result, the development of vision through the strabismus can be permanently damaged. Therefore, it is particularly important to treat squint in children early.
Heterotropy - manifest strabismus
In the case of manifest squint, the shift of the visual axis is visible, although the degree often depends on the viewing angle. Basically, one distinguishes here:
Accompanying strabismus (Strabismus concomitans)
The accompanying squint is medically as Strabismus concomitans designated. Here, the squint angle remains constant in all eye movements, that is, one eye "accompanies" the other. Spatial vision is not possible, usually the visual acuity of the squinting eye is weaker. Concomitant squinting occurs in children in most cases.
Paralysis squinting (Strabismus paralyticus or Strabismus incomitans) a muscle or a supplying nerve of the eye muscles falls out. As a result, the eye can no longer move completely, it creates a malposition.
Unlike the accompanying squint, paralysis strains affect all ages. Since it usually occurs as a sudden strabismus without warning signals, it comes to double images and a wrong spatial assessment. If the head is held obliquely-sideways, squinting can often be minimized, as the neck muscles place the entire head in an oblique position so that the eye looks straight ahead, even though the eye is looking sideways out of the eye socket.
Latent strabismus - Heterophoria
If strabismus occurs only temporarily, for example when someone is tired or one eye is covered, one speaks of latent strabismus or heterophoria. Everything important to read in the article Heterophoria.
Squinting only describes two deviating lines of sight, so it is a symptom. Affected people can not see good spatial or perceive double images.
Often, it is not easy to determine if someone is really switching. Possible misinterpretations for strabismus: babies often have deep-seated eyelids at the transition to the nose (epicanthus). This creates the falsified impression of aberrant visual axes, although the visual axes of both eyes are the same. This is especially common in Asian babies. This phenomenon is also called pseudostrabism, it has no disease value, since no squint angle is measurable.
When vision is lost in one eye, it gradually fades away for several years. Some people only squint away when they look into the distance. This is called intermittent outward squinting.
Symptoms of paralysis
Due to the paralysis or the failure of a muscle in paralysis strabismus Strabismus here is less noticeable. Because this means that a certain movement of the eye can no longer be carried out. The squint angle depends on the viewing direction. Squinting is not noticeable in many directions, as usually only a special muscle is affected and not all eye muscles are always involved in all eye movements.
Patients are usually already noticed by an oblique head posture, thereby relieving the affected muscle. Those affected by this form of strabismus sometimes see double images and have the need to pinch or shut an eye.
Strabismus: causes and risk factors
Schiel causes are very different. Depending on the age and concomitant circumstances, the symptom squinting can have many reasons. If the strabismus occurs suddenly, nerve damage, infections, tumors or bleeding must be excluded.
Causes of accompanying squint
Corneal injury or retinal changes can trigger concomitant strabismus. When vision is lost in one eye, it gradually fades away for several years.
In children especially a refractive error must be excluded (such as strabismus divergence) - this creates an outward squint. Damage during childbirth or brain development can also cause squinting. Especially premature babies are often affected: One out of five children with a birth weight of 1250g or less will squint in later life.
In adults, the accompanying squint is less common. If one compares the diversity of the accompanying squint, it is striking that adults show a wide range of causes, whereas in children, squinting is often attributable to the same reasons, depending on age.
However, one cause of this type of strabismus is not always clear: the eye muscles and the involved nerves work and the trigger must be deeper in the brain than just in case of a muscle failure. Although the causes ultimately can not be clarified, one usually suspects a deficit in the sensorimotor coupling of some muscles. This means, for example, that the sensors responsible for the position of the eye do not transmit completely correct information about the muscle layer to the brain and thus lead to a malposition. This must be recognized in order to plan the therapy accurately.
Causes of paralysis
The paralysis squint may arise at birth due to brain trauma or brain development. Paralysis of individual muscles is sometimes also due to encephalitis or infection during childhood. Measles viruses, for example, can penetrate into the brain and cause great damage here.
Even strokes, tumors or blood clots can disturb a nerve pathway and thus lead to sudden paralysis strabismus. Since the interconnection of the visual pathway is very complicated and the location of the possible damage is varied, it is often necessary to resort to detailed imaging (MRI) in order to clarify the cause of the strabismus.
Lenticular disorders as a cause of strabismus
Since the optical system is very unstable in the first year of life, even lens disorders can cause squinting. Generally speaking, foresight leads to "internal squinting" (strabismus convergence or esotropia). One or both eyes deviate towards the nose. This is also behind the infantile Schiel syndrome, which accounts for 80 to 90 percent of all parasitic disease. Here, the newborn is already squinting on the world. This baby squint is usually detected in the first six months of life. The brain tries to compensate for the ametropia. However, the movement is linked to the movement, so that it comes to sharper images, but the baby simultaneously switched.
Risk factors in strabismus
Since strabismus is so diverse, there is no single risk factor. Ametropia, which is not treated, premature birth or lack of oxygen during childbirth can lead to strabismus. If you blind yourself in one eye during life, this eye no longer actively participates in seeing, incorrect movements are no longer compensated and within a few years the affected eye begins to squint. There is also a familial accumulation of strabismus that suggests a genetic cause.
Strabismus: examinations and diagnosis
Squinting is not obvious to every patient, but it is often noticed by other people. Squint people, they usually look for themselves a doctor. The correct contact person is first the ophthalmologist, who may later call in a neurologist. The following questions can be asked by the doctor:
- Which eye is affected?
- Is the same eye always affected?
- In which direction does the eye deviate?
- How big is the angle?
- Is the angle the same in all directions?
- Do you see double pictures?
- Do you have other visual complaints?
In some patients, squinting is clearly recognizable as such. But sometimes not, because the squint angle is less than five degrees (microstrabism).The same applies to the extremely rare squint, where an eye-apple is twisted clockwise or counterclockwise. In general, squinting can be recognized with the following methods:
Cover test exposes Strabismus
During the covering test, the person affected must fix the center of a cross on the wall (Maddox cross) with both eyes. Then the ophthalmologist covers one eye and observes it. The squinting eye reveals itself by an adjustment movement in the direction of the fixed point.
The ophthalmologist observes the light reflexes of his visit lamp on the pupil of the infant or toddler from a distance of 30 centimeters. If the reflexes are not at identical positions, there is a squint angle.
Read more about the investigations
- U examinations
Concomitant squinting is treated in infants in several steps. If there is an uncorrected vision defect (for example, hyperopia), the child will be fitted with glasses. In case of unilateral visual impairment (for example, in lens opacities) must be treated accordingly, the underlying disease of strabismus. Afterwards, the ophthalmologist observes for a few months, whether the squint angle evaporates.
If this is not the case, the eyes must be taped alternately starting from the weaker one (occlusion treatment). Thus, an amblyopia (weak-sightedness) can be prevented or, if necessary, pushed back. Because the brain is forced, despite strabismus, to use the weak eye and to train. Occlusion treatment can take years to adequately improve the visual acuity of the weaker eye. The remaining squint angle can then be corrected surgically.
If the accompanying squint occurs after the age of six, the occlusion treatment is eliminated. Otherwise, children, adolescents and adults receive the same treatment as toddlers.
When paralyzing squint, the cause (stroke, for example) must be treated as far as possible. Occasionally, a squint angle can also be compensated with a prismatic lens. If the eye muscle is permanently paralyzed, a squint operation may help.
Read more about the therapies
Strabismus: Disease course and prognosis
There is no general prognosis for strabismus. If somebody shuts one eye because of loss of vision, this strabismus will not just disappear on its own. However, if strabismus occurs in a child due to ametropia and is treated promptly, it may grow within a few months or less.
The course of the disease is therefore highly dependent on the cause. The better the trigger, the better the prognosis. The later and more sudden the squinting, the more difficult the treatment. A prognosis must therefore be made individually by the attending physician. Often, an interdisciplinary approach with neurologists, ophthalmologists, paediatricians, radiologists and internists is called for all the causes of strabismus to be able to cover.