Squint
With strabismus or strabismus ( ancient Greek στραβισμός strabismós "strabismus") is an eye muscle imbalance disorder , which is expressed in a misalignment of both eyes to each other. Here, the direction differs their lines of sight when viewing ( fixing ab) of an object temporarily or permanently from each other. The extent and shape of this misalignment can be very different, also depending on the distance to the object and the direction of view, can be measured relatively precisely with various methods and result in one or more so-called squint angles . There are forms of strabismus that are usually not pathological, but merely an expression of a standard variant . They represent the physiological deviation from an ideal form. However, many forms of strabismus are serious illnesses with severe functional visual impairments and as such go far beyond a purely cosmetic problem. They can be congenital, acquired through an accident or developed in the course of other diseases (for example albinism or stroke ). It is common to early childhood and congenital strabismus that starting treatment as early and consistently as possible is a crucial prerequisite for improvement or even healing.
In Central Europe , about six percent of the population is affected by a pathological squint. The ability to squint is inheritable . Diagnostics and therapy are located in the ophthalmological specialty areas of strabology and neuroophthalmology .
Diagnostics and examination
A distinction can be made between two basic framework conditions for assessing and measuring the position of the eyes to one another and their motility : apparatus-based and free-space examinations. While squint angle measurements take place in a more artificial environment by means of apparatus arrangements, examinations in free space represent a more natural environment. This can influence the values determined. Regardless of the method used, a strabismus deviation is usually documented in degrees , more rarely in prism dioptres or, as in the linear strabometry method , in millimeters.
It is always necessary to assess the position of the eyes at a distance and near , as there are a number of strabismus diseases that vary depending on the fixation distance . A prerequisite for a reliable quantitative assessment is the ability of the patient to fixate on an object or light. The more attentive and concentrated he participates in the examination, the more reliable the results of a squint angle measurement, which are based on both objective assessment criteria (adjustment movements) and subjective information from the patient (provoked diplopia and confusion ). At the same time, it is almost always possible to make a qualitative statement about the shape and direction of a squint even in infancy , which is often sufficient to initiate suitable therapeutic measures. The assessment of the corneal reflexes ( Hirschberg test ) of a small flashlight and the inspection of the subsequent movements can provide an initial information. The so-called Brückner test (synonym: fluoroscopic test according to Brückner ) is also suitable for identifying strabismus on the basis of the fundus reflexes. However, this is not sufficient to establish an indication or even a dosage basis for a squint operation.
The covering test (synonym: cover test ) is one of the most common examination methods to identify strabismus . It is used in free space and is often carried out with various aids, for example a prism bar , in order to be able to precisely measure squint deviations in the distance and near. Different dissociating color filters and a so-called Maddox cross (a cross equipped with two scales and a central fixation light for an examination distance of five meters) are also part of the examination arrangement. The type and extent of a squint can differ not only in different fixation distances, but also in different viewing directions. This is particularly important when eye muscles are affected, which have to fulfill several functions depending on the direction of gaze , for example raising , lowering or rotating an eye. In addition, in the case of some strabismus diseases, especially paralysis strabismus, the extent of a squint angle depends on which eye is currently fixing.
Detailed movement and position analyzes of the eyes therefore require appropriate examination environments that allow up to 180 measurements in the different viewing directions and can take into account the documentation of horizontal, vertical and rotational deviations. Such extremely complex motility schemes are carried out in free space with a so-called Harms wall (also: Tangententafel according to Harms ) or with a so-called synoptometer (according to Cüppers ). Both methods support graphic documentation of the findings obtained using a special coordinate system.
Examination methods , which in particular also use the subjective information of the test person , are the coordination with the Hess screen , measurements with the Lee screen , as well as haploscopes such as the phase difference haploscope (according to Aulhorn ) or the synoptophore . For the measurement of Zyklodeviationen , so rotational deviations, the suitable Deviometer according Cüppers, the so-called with a rotating dove prism is provided.
The diagnosis and documentation of motility disorders can be supported by special computer applications.
Development in Infancy
A short-term misalignment of the eyes in infancy, colloquially also occasionally referred to as "losing the eye" , is often observed in the first months of life with individually different frequencies. At this age it is usually a side effect of a neural learning process. During this learning process, the sensory and motor basics of binocular vision develop between the 2nd and 4th month of life, resulting in precise coordination of eye movements and their parallel position. During this time there can be a temporary loss of the parallel position ("losing the eye"), which is normally due to the not yet fully completed development of the two-eyed vision and usually also has no pathological background. The differentiation between a normal learning process and a pathological disorder is of particular importance for parents and doctors. However, if such short-term misalignments occur frequently, persist for a long time or manifest themselves only to a very small extent (silver look), an orthoptist or ophthalmologist should use his special examination techniques to determine the cause of the disorder so that it can then be treated as early as possible .
Latent squint
| Classification according to ICD-10 | |
|---|---|
| H50.5 | Heterophoria - Latent squint |
| ICD-10 online (WHO version 2019) | |
As latent (hidden) squinting an eye muscle imbalance is referred to, by a mechanism (Binocular) binocular vision , the so-called fusion can be compensated and balanced. This is generally symptom-free and often without the affected person even noticing. This is why we speak of a standard variant or a deviation from an ideal shape ( orthophoria ). The causes of such a latent squint are often congenital and, in addition to the purely motoric, can also be uncorrected ametropia (especially clarity ) or anatomical conditions. Heterophoria can be found in around 70–80% of all people.
Overtiredness, illness, stress, poisoning or other factors can lead to complaints in the form of double vision , headache or eye pain and concentration disorders when trying to compensate for this coordination disorder, which is what gives latent strabismus a certain disease value. The symptoms triggered in this way are referred to as asthenopic symptoms or asthenopia . The extent of a latent squint does not necessarily have to be decisive for the severity of the symptoms. A typical trigger for the occurrence of such problems is, for example, the increase in visual stress at a display workstation .
If a latent squint can no longer be controlled and compensated for by the person concerned, this is referred to as decompensated heterophoria, which now has a manifest squint angle. This may sound confusing to the layperson, but it is nonetheless part of the clinical picture of latent strabismus.
to form
As with overt strabismus, there are different forms that are defined by the direction of their deviation. A latent squint, in which there is a deviation inwards towards the nose, is called esophoria , and one towards the temple is called exophoria . Latent deviations upwards are called hyperphoria , downwards hypophoria . A latent curl squint is referred to as cyclophoria , depending on the direction of the deviation, incyclophoria or excyclophoria .
therapy
Therapy is not necessary if there are no or only minor symptoms and stable binocular vision is available. This is the case for most people. However, there are scenarios in which the subjective complaint situation or an objective assessment of the findings can make therapeutic measures necessary. These are based on many different factors and test results. The result can be the simple prescription of suitable glasses to correct an existing ametropia . Or it is necessary to adapt special glasses with a so-called prismatic effect , which are used to correct the latent squint itself. Orthoptic exercise treatments or surgery can also be considered as part of a treatment. A necessary therapy often consists of a combination of the above measures.
Manifest squint
Synonym: heterotropy
With heterotropia which is lasting and constant deviation of an eye designated by a common line of sight, regardless of shape and underlying causes. It's always pathological .
to form
Depending on the direction of a squint deviation, the following forms of manifest squint exist:
- Inward or internal strabismus ( convergent strabismus or esotropia )
- External or external squint ( strabismus divergent or exotropia )
- Height squint ( strabismus verticalis or hypertrophy or hypotropia )
- Strabismus ( rotatory strabismus or cyclotropy - excyclotropy or incyclotropy )
Depending on the clinical picture, these different forms of strabismus can occur in all possible combinations.
Accompanying strabismus
Synonym: strabismus concomitans
An accompanying strabismus is a generally manifest, cosmetically visible squint of one eye (or alternately both eyes), which is always approximately the same in all viewing directions, but in which the deviations in distance and near can vary greatly. The extent of a squint angle at the same distance can also be very different (fluctuating angles). The mobility of the squinting eye is usually not restricted. The term concomitans therefore means nothing else than that when looking around, the cross-eyed eye can follow the leading, non-cross-eyed eye in all directions without restriction . The pulling force of the eye muscles involved in a non-paretic squint is usually the same, but the balance between agonist and antagonist does not maintain a parallel position, but a squint position.
| Classification according to ICD-10 | |
|---|---|
| H50.- | Other strabismus |
| H50.0 | Strabismus concomitans convergens |
| H50.1 | Strabismus concomitans divergens |
| H50.2 | Strabismus verticalis |
| H50.3 | Intermittent strabismus concomitans |
| ICD-10 online (WHO version 2019) | |
Almost always congenital, it usually manifests itself in small children and, if left untreated, results in lifelong weak vision of the cross-eyed eye, so-called amblyopia , which in the worst case has to be equated with one-sided blindness . As a rule, the visual impression of the cross-eyed eye is suppressed by the brain (suppression) in order to avoid the perception of annoying double images. However, since adequate stimulation of the sensory cells is necessary for the development of normal visual acuity , this inevitably leads to the described functional visual impairment. Another lifelong deficit can consist in the lack of spatial vision , at least in its massive limitation.
Although internal squint is by far the most common form of congenital secondary squint, combinations of different forms of squint are not uncommon. Often there is a vertical squint of the eye facing the nose (adducted) in the form of a raised position ( strabismus sursoadductorius ) or a lowered position ( strabismus deorsoadductorius ). Another form of vertical squint is the so-called dissociated vertical squint. All of these squint forms are part of the congenital squint syndrome , which also includes eye tremors ( nystagmus ).
Even if there is a low level of suspicion or a family disposition , affected children should be presented immediately to an ophthalmologist's practice with a corresponding special department ( visual school ). The age of the child is irrelevant. Even small children under 1 year of age can be adequately examined by experts. The earlier suitable therapeutic measures are initiated, the higher the chance of a successful treatment and the better the prognosis for preventing one-sided impaired vision and creating the conditions for the development of spatial vision.
Manifest strabismus diseases are never a purely cosmetic problem, but result in massive functional deficits that can influence the later career choice and thus directly affect the quality of life of those affected.
One-sided and two-way squint
With one-sided (monolateral) squint, there is always a guide eye , while only the guided eye takes a squint position. With alternating (alternating) squint, there is no fixed guide eye, which means that once the right eye and another time the left eye crosses. Here, too, the visual impression of the eye squinting straight is generally suppressed by the brain. If the alternating squint appears to be an even more serious form at first glance, since it affects not just one eye, but both, this fact has a decisive advantage in therapeutic reality: the visual acuity of both eyes will be different, whether organic or otherwise nothing opposes it, develop almost equally well, since none of the eyes is preferred or excluded from basic use. Amblyopia can thus be largely avoided. From a prognostic point of view, an alternating squint is therefore to be assessed as positive from the aspect of the general threat of functional impaired vision.
Intermittent squint
Intermittent squint occurs periodically , manifests itself almost exclusively in the form of external squint ( exotropia ) and is characterized by sensory peculiarities and adaptation processes. The interaction of certain retinal cells in both eyes ( retinal correspondence) is abnormal in the deviation phase, but normal in the compensation phase. Furthermore, in the phase of deviation, so-called panoramic vision , the classification of the visual fields of both eyes in a sensory, egocentric space, is evident . Affected persons localize with the guide eye and at the same time classify the visual impression of the deviating eye topographically correctly. In the case of very large squint angles, the gaps between the fields of vision are filled in psycho-optically and, in addition, form a common visual space. Due to the sensory peculiarities, this form of squint is clearly distinguishable from the decompensating exophoria , in which double image perception occurs with normal retinal correspondence in the decompensation phase.
There are the following types of intermittent external squint:
- Neutral type with approximately the same squint angle in distance and near
- Divergence excuse type with a significantly larger far than near squint angle
- Pseudodivergence excuse type with the same near and far angle, but in which the near angle is compensated more often
- Type of convergence insufficiency with a larger near-than-distant squint angle.
The most common forms are the neutral and pseudodivergent excesses types.
therapy
In the case of congenital strabismus, the therapeutic measures primarily serve to minimize the negative effects that the strabismus has on the vision of the affected eye and the quality of binocular vision. The cosmetic aspect of squinting is also usually significantly improved. In general, various procedures and components are required for the treatment: determination and prescription of glasses, occlusion treatment and, if necessary, one or more strabismus operations. None of these treatment components serve as a substitute for another. They are only useful and effective in combination, provided that no alternative measures are available from a medical point of view.
The treatment of congenital strabismus and its secondary diseases lasts around 12 to 13 years of age. A functional improvement is almost exclusively only possible in childhood and when treatment is started as early as possible. The later therapy is started or the earlier it is stopped, the worse the chances of success. In adults, the treatment of amblyopia and the development of binocular vision is usually no longer possible. However, cosmetic improvements can be achieved using appropriate surgical procedures.
Eyeglass correction
Correction of glasses has an impact on visual acuity and in some cases on the position of the eyes. Usually an ophthalmological examination ( refraction measurement ), which is prepared with special eye drops to temporarily dilate the pupil and eliminate accommodation , is usually carried out to determine whether the patient has ametropia and needs glasses correction . This is particularly necessary in the case of a high degree of hyperopia ( hyperopia or, in general, farsightedness) or accommodation-related squint, since this refractive error in the uncorrected state always has a more or less pronounced influence on the size of a squint angle.
In some patients, the squint angle is influenced by glasses correction in such a way that it is barely visible or not at all. This circumstance in no way replaces a plaster occlusion, but in some cases it can make a squint operation superfluous.
Occlusion treatment
In this indication, occlusion therapy (occlusion = closure) is a measure that is used in childhood and influences the visual acuity of the cross-eyed eye. If there is a unilateral strabismus, an appropriate treatment is started immediately. The purpose of this measure is to force the cross-eyed eye to fixate by excluding the healthy eye from seeing with an appropriate aid. Common methods are skin occlusion using a plaster, as well as spectacle occlusion with foils of different light permeability. The type, duration and rhythm are discussed with the ophthalmologist or the orthoptist. If an alternating strabismus (see above) is diagnosed, an occlusion treatment can be dispensed with with reliable and close-knit checks, as long as the visual acuity of both eyes is equally good. In some cases it may be necessary to occlude the amblyopic, cross-eyed eye ( inverse occlusion) over a certain period of time and in a given rhythm . This measure requires certain findings and requires more short-term controls.
Penalization
Penalization ( Latin poena , 'punishment') influences the guidance behavior of the eyes at different fixation distances. In this procedure, the better eye is drastically hindered by the administration of accommodation-paralyzing eye drops ( atropine ) while seeing nearby, while the cross-eyed eye is prescribed spherical overcorrection using plus lenses of 1–3 diopters. As a result, the cross-eyed eye only fixes in the vicinity, while the healthy eye takes over the fixation in the distance. This form is called near penalization . In the ideal case, the result is a near-far alternation of the cross-eyed and healthy eye. In contrast, there is a remote penalization . Here, atropine and an additional spherical overcorrection with 3 dpt is administered to the healthy guide eye, while the cross-eyed, amblyopic eye receives a complete correction of its ametropia. This leads to a reduced visual acuity of the guide eye in the distance and is supposed to be more effective than the near penalization because of the deterioration in the depth of field . The last variant known is complete penalization , which by atropinization of the healthy eye and omitting the spectacle lens in the case of hyperopia or the insertion of a strong minus lens at all fixation distances no longer allows a sharp image. It is considered to be the most effective form of penalties.
Penalization should only be carried out with foveolar fixation of the amblyopic eye and a visual acuity between 0.2 and 0.8. Then it is quite suitable as an alternative to occlusion, but requires a longer treatment period.
Pleoptics
Pleoptics ( pleos , Greek: “full”) uses apparatus-based treatment methods that influence the fixation behavior and thus the visual acuity of the cross-eyed eye. As an active intervention in the treatment of amblyopia, pleoptic procedures have been replaced by the much more cost-effective and more practicable occlusion therapies in recent decades. They are still used as a supportive measure under certain circumstances, but require a great deal of experience on the part of the treating specialist.
Orthoptics
Orthoptic (from Greek: ὀρθοπτική , " straight vision ") treatments influence the quality of binocular vision and the cooperation between both eyes. Various methods can be used for this, which can be carried out with special devices (haploscopes) or with very simple aids to achieve a successful course of therapy.
Squint operation
A squint operation affects the mechanics, mobility and position of the eyes to one another. It can be considered when the extent of latent or manifest squint, i.e. the squint angle, is so great that the prerequisites for the development or maintenance of binocular vision (binocular functions) are not given or central fixation is not possible. The primary aim is a functional improvement. Squint operations influence the functioning of one or more eye muscles. The primary aim is to reduce the size of a squint angle by the amount that appears most sensible to the medical and functional goals. There are different procedures, techniques and methods for shortening or shifting muscles or changing the so-called roll-off distances. In cases where there is a particularly large squint angle, surgery on both eyes may be necessary, even if only one eye is affected by the squint disease. In a squint operation, the eye is neither removed nor incised. One technique in which the conjunctiva is opened with very small incisions on the order of just a few millimeters is minimally invasive strabismus surgery , which is supposed to lead to faster rehabilitation.
In the case of congenital and early childhood strabismus, there are different approaches with regard to the optimal time for the operation. An early operation in toddlers aged two to three years supports the development of binocular vision. If such two-eyed vision is present in a certain quality, this generally ensures a more favorable prognosis with regard to a long-term stable surgical result. A later operation in the 5th to 6th year of life enables a much more precise examination, indication and dosage of the intervention. Which of the two variants can be considered must be assessed on a case-by-case basis. There is agreement that a squint operation should always be carried out before starting school. Occlusion treatment that has already been carried out successfully improves the prognosis, but is still indicated postoperatively.
In rare cases, squint operations may result in the result exceeding the planned reduction in the squint angle. As a result, the eye will squint in the opposite direction. If this is not intended and has been achieved through targeted overdosing, it is possible to carry out a (partial) revision after a certain period of time in order to achieve the originally intended result.
On the other hand, cases are known in which a squint operation carried out according to the usual dosage scheme has lagged significantly behind the aim of a certain angle reduction aimed at.
Microstrabismus
Synonym: microtropy
Symptoms
| Classification according to ICD-10 | |
|---|---|
| H50.4 | Other and unspecified strabismus concomitans - microstrabismus |
| ICD-10 online (WHO version 2019) | |
Microstrabism is a manifest, one-sided internal squint that is very small in size and on the sensory basis of which binocular vision (simultaneous vision , fusion, spatial vision) can often develop. This is made possible by an abnormal and inferior quality, but often functioning cooperation of both eyes that is adapted to the circumstances (see also: retinal correspondence ). It is not uncommon for an early start of treatment to ensure that the cross-eyed eye learns to focus on the point of sharpest vision. In such cases, the prognosis for avoiding amblyopia and developing subnormal binocular vision may be favorable.
A distinction is made between congenital forms and those that have manifested themselves as a result of years of strabismus treatment and / or surgery ( consecutive microstrabismus) or are caused by other eye diseases ( secondary microstrabismus).
therapy
Treatment is in the form of prescription glasses, if necessary. In addition, a consistent occlusion treatment is required up to 12/13 Year of life carried out, the scope and form of which depends on the respective circumstances and findings.
Because of their cosmetic inconspicuousness, microstrabisms and their effects are very often underestimated. They are sometimes referred to in a humiliating way as "silver look". However, an untreated microstrabismus can lead to severe amblyopia just as conspicuous congenital strabismus.
Normosensory late squint
Symptoms
The normosensory late squint is usually acutely occurring, manifest internal squint, begins between the ages of 3 and 7 and is characterized by a number of other criteria that distinguish it from other forms of squint. The symptoms are most closely comparable to those of decompensated heterophoria . The sensory development of binocular vision is already complete when the disease occurs. Often the patients complain of double vision and therefore narrow one eye. However, it occasionally happens that the visual impression of the cross-eyed eye is suppressed, as is the case with congenital accompanying strabismus.
The identification of the actual start of strabismus often poses a not inconsiderable problem in recognizing the clinical picture. The detailed and detailed collection of anamnesis is therefore essential for the timely initiation of suitable treatment measures.
therapy
Normosensory late squint requires immediate therapeutic intervention to restore the lost fusion ability. In addition to the Glasses Ordinance, the primary measure for this is the adaptation of corresponding prisms as an interim solution. In general, an immediate squint operation is indicated, since even older children can lose some or all of their binocular vision. Part-time occlusion, depending on the findings, may be necessary. In some cases, in which the picture of an accommodative strabismus is present, the correction of an existing hyperopia can reduce the squint angle in such a way that this leads to a restoration of the ability to fuse.
The number of cases of normosensory late squint makes up only about 5–7% of all cases of strabismus. If treatment is started in good time, the prognosis for healing is good. Nevertheless, statistical evaluations show that not all patients develop full binocular vision again, even after optimal therapeutic care. In any case, even with a good treatment result, regular checks should be carried out for several years, since recurrences can occur.
Accommodation squint
Due to the reflex control loop of convergence and accommodation, accommodative strabismus is based on the assumption that uncorrected or undercorrected hyperopia can be a decisive factor for the occurrence and extent of internal squint. Either the patient foregoes sharp vision while maintaining the parallel position of the eyes, or he compensates for his clarity by means of accommodation and thus triggers an excessive convergence reaction and thus internal squint. A purely refractive form of internal squint is rather the exception. They are therefore differentiated from innervational variants of the so-called convergence excess , which is associated with a large squint angle in the vicinity. All accommodative forms of convergent strabismus require full eyeglass correction.
Purely accommodative form
It is assumed here that the necessary full correction of an existing hyperopia with suitable glasses completely eliminates an existing internal squint, which presupposes the existence of normal binocular vision. In this respect, the occurrence of a purely refractive convergent strabismus is at best conceivable as a normosensory late squint or as a periodically occurring event. In practice, on the other hand, a closer examination of the binocular functions and visual acuity reveals a large majority of these cases to be a primary microstrabism that is decompensated by accommodative influences. Science has therefore established that, with the appropriate predisposition, hyperopia can be a very effective trigger and intensifier of internal squint, but is not its cause.
Partially accommodative form
The refractive, partially accommodative form of a convergent strabismus is characterized by a greater or lesser influence of hyperopia on the onset and extent of internal strabismus. In this respect, the provision of appropriate glasses correction is necessary, but it has different effects. Although it by no means excludes the need for a squint operation, it usually influences the dosage accordingly if you do not want to run the long-term risk of consecutive external squint. The partially accommodative component itself already implies that the basic causes of strabismus are more to be found in the pathology of binocular vision and thus a complete healing is rarely achieved.
Other forms
A circadian or cyclic squint is a sudden onset of internal squint that usually manifests itself periodically - usually every two days - which has led to the English term "alternate day squint". In times when the squint does not occur, no significant latent deviation is detectable. It is very rare and its cause is unknown.
As strabismus in senium a spontaneously occurring squinting in advanced adulthood is called. Its causes are different and range from organic diseases to decompensation of already existing heterophorias.
Paralysis squint
Synonyms: strabismus paralyticus or strabismus incomitans
Causes and symptoms
| Classification according to ICD-10 | |
|---|---|
| H49.- | Paralytic strabismus |
| H49.0 | Paralysis of the oculomotor nerve |
| H49.1 | Paralysis of the trochlear nerve |
| H49.2 | Paralysis of the abducens nerve |
| H49.9 | Paralytic strabismus, unspecified |
| ICD-10 online (WHO version 2019) | |
Damage in the peripheral course of the ocular muscle nerves or their core areas, at the transfer points between nerve and muscles or on the muscles themselves lead to a reduction in the function of one or more eye muscles and thus to paralysis. This always goes hand in hand with restricted movement of the affected eye. The cross-eyed eye can therefore no longer follow the healthy eye unrestrictedly in all directions of gaze , unlike with accompanying strabismus. The extent can range from minor paresis to complete paralysis . Paralysis can occur on one or both sides and affect the following cranial nerves :
- Oculomotor nerve (III. Cranial nerve)
- Trochlear nerve (IV cranial nerve)
- Abducens nerve (VI. Cranial nerve)
Paralysis strabismus can occur in isolation or as a combination of failures of several cranial nerves. Subjectively, it becomes noticeable through double vision (diplopia) and disorientation. The latter are the result of a false egocentric localization that occurs when patients fixate with their hemiplegic eye. In addition, affected individuals often take compensatory head postures one with the aim of either the disturbing double image as possible far from the usual use sight to see banish, or binocular easy. Objective signs are:
- an incommitting squint angle, which varies in size depending on the direction of view and which increases in the direction of pull of the affected muscles,
- a large secondary angle that is larger when fixed with the affected eye than when fixed with the healthy eye,
- a restriction of the monocular mobility in the direction of the paralyzed muscle and thus the monocular field of vision,
- in some cases, a retraction of the eyeball,
- Secondary changes in the paretic muscle and its ipsilateral antagonist.
According to their specific symptoms, sometimes in combination with ptosis , eye muscle paralysis requires very differentiating and complex diagnostic procedures for the correct identification of the clinical picture and the affected areas. They are seldom congenital, but mostly acquired through accidents or illness. Causes can include circulatory disorders , a stroke, autoimmune diseases such as multiple sclerosis , tumors , aneurysms or inflammation . Eye muscle paralysis caused by painful inflammatory processes is, for example, the so-called orbital tip syndrome or Tolosa Hunt syndrome . In addition, a number of congenital ocular muscle pareses are known, for example Duane syndrome .
Supranuclear eye movement disorders
Special forms of movement disorders can arise if the lesion is located beyond the ocular muscle nuclei in the area of the superordinate gaze centers and thus, by definition, no longer belongs to the group of paralysis strabismus. As a rule, these are disorders of certain movement patterns in both eyes, i.e. eye movements. Such complex functional failures can be associated with paralysis strabismus or occur in isolation. The most important clinical pictures include vertical and horizontal gaze paralysis , vergence disorders , nystagmus, oculomotor apraxia , disorders in the vestibulo-ocular reflex circuit , and disorders of optokinetic nystagmus . In addition, there are so-called prenuclear paralysis symptoms, which usually also lead to a squint. One of the best-known diseases of this group is internuclear ophthalmoplegia (INO). If an INO occurs in combination with a horizontal gaze paralysis, one speaks of the clinical picture of the one and a half syndrome .
therapy
As with all neurological disorders, once the cause has been clarified, treatment is primarily in the hands of a neurologist. Depending on the underlying disease, the regression of an eye muscle paralysis can proceed very differently in terms of the findings and the duration. With paralysis strabismus patients usually suffer from the annoying double vision. These should be treated either with prism glasses or, if this is not possible, by covering one eye. However, for the duration of the occlusion, this results in the temporary loss of binocular vision and a correspondingly large restriction in the visual field.
Surgical treatment may be necessary if the paralysis has not or only insufficiently regressed within a foreseeable period. However, eye muscle surgery is usually only considered after six months at the earliest and is to be regarded as healing of the defect . In general, one goal of such interventions is to shift the field of single binocular vision into the normal field of vision. As a result, in the ideal case, the patient no longer sees twice when the head is straight and no longer has to assume a forced head posture to achieve this state. Double vision can only occur again when the eyes are turned. However, general statements are hardly possible. It is not uncommon for paralysis to change the muscle tissue after a certain period of time . Treatments and their results are usually as individual as the clinical picture itself.
Since the 1980s, the highly effective neurotoxin botulinum toxin has been used in certain cases for preoperative diagnostics or as an alternative to a strabismus surgery. Disadvantages described here are the lack of meterability and a decrease in the treatment effect.
Mechanically caused squint forms
| Classification according to ICD-10 | |
|---|---|
| H50.6 | Mechanically caused strabismus |
| ICD-10 online (WHO version 2019) | |
A number of strabismus diseases are known which, due to mechanical disabilities or structural changes, trigger corresponding movement disorders. These include, for example
- the Brown syndrome , a thickening of the tendon of the abdominal superior ,
- the orbital floor fracture , in which muscle and connective tissue can be trapped in a fracture fissure,
- as well as endocrine orbitopathy , in which the muscle structures themselves can be pathologically changed due to inflammatory processes.
The so-called traction test (also: tweezer pull test ), a method to test the passive mobility of the eye, is used to differentiate between actual eye muscle paralysis and mechanical or fibrotic movement restrictions ( pseudoparesis ) .
Pseudostrabism
With Pseudostrabismus refers to a some specific situations cosmetically fake squint of the eyes, but showing no strabismus with appropriate clinical significance in the medical sense. A classic example of this is the epicanthus medialis , which usually occurs in small children and in many peoples with the Mongoloid phenotype and can be deceptively similar to an internal squint with a wide bridge of the nose and nasally shortened eyelid gap. Likewise, a squint can be simulated by certain positions of the pupillary light reflexes or by facial asymmetries . A congenital macular ectopy , a distortion of the yellow spot on the retina , can also simulate a squint. The poet Annette von Droste-Hülshoff apparently suffered from this disease, which is why one occasionally speaks of the Annette von Droste-Hülshoff syndrome in these cases .
Cultural and social aspects
Squint was already mentioned in medical texts in the Ebers Papyrus around 1550 BC. BC and later mentioned in the Corpus Hippocraticum . Galen then describes seven external eye muscles in the 2nd century AD and interprets the squint as an overactive or cramp of an eye muscle.
In the 7th century, the Byzantine doctor Paulos of Aigina suggested treating small children with a mask and sitting in front of a lamp in his book Hypomnema .
Since the emergence of ancient high cultures , differentiated representations of the eyes in works of art have been known, in which in some cases a clear squint is recognizable. However, this is almost exclusively a divergence position, which is partly interpreted as an expression of pain and sadness, but also as a feeling of happiness and ecstasy.
The high culture of the Maya saw squinting as an ideal of beauty and an identification with the sun god that characterizes those affected. Attempts were made to provoke this even in small children with a ribbon tied around the head with a stone dangling from it.
On the other hand, at the end of the 19th century, the Italian doctor, forensic doctor and psychiatrist, Cesare Lombroso , taught that "squinting" was an essential characteristic of the human criminal type, along with "handle ears", "receding forehead" and "crooked nose" .
Actors such as Ben Turpin , Marty Feldman , Otto Waalkes , Dieter Hallervorden or Mirco Nontschew use strabismus for the purpose of comic effects.
Colloquially, squinting means : looking diagonally from the side for something or keeping an eye on something .
literature
- Herbert Kaufmann : Strabismus . 5th completely revised edition with Heimo Steffen. Georg Thieme Verlag, 2020, ISBN 978-3-13-241330-6 .
- Josef Lang: Microstrabismus. (Library of the ophthalmologist, No. 62). Enke, Stuttgart 1982, ISBN 3-432-83502-7 .
- Axenfeld, Pau: Textbook and Atlas of Ophthalmology . With the collaboration of R. Sachsenweger u. a. Gustav Fischer Verlag, Stuttgart 1980, ISBN 3-437-00255-4 .
- Rudolf Sachsenweger: Neuroophthalmology . 3. Edition. Thieme Verlag, Stuttgart 1983, ISBN 3-13-531003-5 .
- Alfred Huber, Detlef Kömpf: Clinical Neuroophthalmology . 1st edition. Thieme Verlag, Stuttgart 1998, ISBN 3-13-103561-7 .
- Katja Bossow: From the beginning of the strabismus treatment to the emergence of the profession of orthoptist. In: Würzburger medical history reports , 23, 2004, pp. 528-534.
- Elfriede Stangler-Verschrott: Abnormal eye position as a statement in the fine arts of Europe . In: Spectrum of Ophthalmology , 2018, doi: 10.1007 / s00717-018-0392-y
Web links
- Recognize visual disturbances and risks at an early stage - kindergesundheit-info.de: independent information service of the Federal Center for Health Education (BZgA)
- Guideline No. 2 of the Professional Association of Ophthalmologists in Germany, BVA - Basic Ophthalmological Diagnostics in Children in the First Two Years of Life (PDF; 73 kB)
- Guideline No. 3 of the Professional Association of Ophthalmologists in Germany, BVA - Basic Ophthalmological Diagnostics in Children from 3 to 6 Years of Age (PDF; 95 kB)
- Guideline No. 26a of the Professional Association of Ophthalmologists in Germany, BVA - Amblyopia (PDF; 626 kB)
- Guideline No. 26b of the professional association of ophthalmologists in Germany, BVA - non-paretic squint
- Guideline No. 26c of the professional association of ophthalmologists in Germany, BVA - eye muscle surgery for non-paretic squint and nystagmus-related head posture
- Guideline No. 27 of the Professional Association of Ophthalmologists in Germany, BVA - Paretic Strabismus
- Guideline No. 27a of the professional association of ophthalmologists in Germany, BVA - eye muscle surgery for paretic squint
- Guideline No. 31 of the Professional Association of Ophthalmologists in Germany, BVA - Ophthalmological screening examinations of premature babies (PDF; 3.9 MB)
- Bielschowsky Society for Strabismus Research and Neuroophthalmology
- BVA - Professional Association of Ophthalmologists in Germany V.
- DOG - German Ophthalmological Society e. V. (PDF; 122 kB)
- BOD Professional Association of Orthoptists in Germany V.
- VDOÖ Association of qualified orthoptists in Austria
- SVO / ASO Swiss Association of Orthoptists
- Detailed overview article with pictures
- Treatment of strabismus. Information from the VDOÖ
- Sk2 guideline for visual perception disorders (PDF) of the AWMF , status 04-2017; accessed on January 26, 2018
Individual evidence
- ↑ Pschyrembel - Clinical Dictionary. 256th edition. edited under the direction of Christoph Zink. De Gruyter, Berlin / New York 1990, ISBN 3-11-010881-X .
- ↑ Guideline No. 26b of the Professional Association of Ophthalmologists in Germany, BVA - Non-paretic strabismus
- ↑ D. Wieser: [Illustration of the incomitance pattern in congenital unilateral obliquus superior paresis with the synoptometer (author's transl)]. In: Clinical monthly sheets for ophthalmology. Volume 178, Number 2, February 1981, pp. 95-101, doi: 10.1055 / s-2008-1055306 . PMID 7230707 .
- ^ Siegfried Priglinger , Michael Buchberger: Eye motility disorders - computer-aided diagnosis and therapy. Springer Verlag, 2005, ISBN 3-211-20685-X .
- ↑ Inge Flehmig: Normal development of babies and their deviations: early detection and early treatment . Georg Thieme Verlag, 2007. ISBN 9783135606071
- ↑ Horwood A: Neonatal ocular misalignments reflect vergence development but rarely become esotropia. . In: Br J Ophthalmol . 87, No. 9, 2003, pp. 1146-50. doi : 10.1136 / bjo.87.9.1146 . PMID 12928285 . PMC 1771854 (free full text).
- ↑ Candy TR: The Importance of the Interaction Between Ocular Motor Function and Vision During Human Infancy. . In: Annu Rev Vis Sci . 5, 2019, pp. 201-221. doi : 10.1146 / annurev-vision-091718-014741 . PMID 31525140 . PMC 7133444 (free full text).
- ↑ Herbert Kaufmann, Heimo Steffen (Ed.): Strabismus . 4th edition. Georg Thieme Verlag, Stuttgart, New York 2012, ISBN 978-3-13-156934-9 , pp. 193 (660 p., Limited preview in Google Book search).
- ↑ I know that I don't know anything? Comments on occlusion treatment. In: The ophthalmologist. Verlag Springer, Berlin / Heidelberg, ISSN 0941-293X , Volume 99, Number 10 / October 2002.
- ^ Daniel S. Mojon: Minimally invasive strabismus surgery. In: Expert Review of Ophthalmology. Vol. 5, No. 6, 2010, pp. 811-820, doi: 10.1586 / eop.10.72 .
- ↑ Information from the Lübeck University Eye Clinic
- ^ Herbert Kaufmann: Strabismus. With the collaboration of W. de Decker u. a. Enke, Stuttgart 1986, ISBN 3-432-95391-7 , p. 186.
- ^ Herbert Kaufmann, Heimo Steffen: Strabismus . 4th edition, Georg Thieme Verlag, Stuttgart, New York 2012, p. 234 ff. ISBN 3-13-129724-7
- ^ Herbert Kaufmann: Strabismus . With the collaboration of W. de Decker u. a. 3. Edition. Georg Thieme Verlag, 2003, ISBN 3-13-129723-9 , p. 469 ff. Online at: books.google.de
- ↑ Peripheral ocular muscle and nerve palsy. In: Guidelines for Diagnostics and Therapy in Neurology. 3rd revised edition. Georg Thieme Verlag, Stuttgart 2005, ISBN 3-13-132413-9 . (AWMF guidelines register: No. 030/033).
- ↑ Botulinum toxin injections to treat strabismus. Springer Verlag, Berlin / Heidelberg, ISSN 0941-293X .
- ↑ G. Meyer-Schwickerath: The Annette von Droste-Hülshoff syndrome *. In: Clinical monthly sheets for ophthalmology. 184, 1984, p. 574, doi: 10.1055 / s-2008-1054558 .
- ↑ M. Pawlak, A. Gotz-Wieckowska: [Annette von Droste-Hülshoff syndrome-case report]. In: Klinika oczna. Volume 112, number 4-6, 2010, pp. 135-137, PMID 20825069 .
- ^ Hermann Grapow : Sick, Illness and Doctor. Berlin 1956 (= outline of the medicine of the ancient Egyptians , 3), p. 54 and 138.
- ↑ Katja Bossow: From the beginning of the strabismus treatment to the emergence of the profession of orthoptist. In: Würzburger medical history reports 23, 2004, pp. 528-534; here: p. 528 f.
- ^ Franz Krogmann: Strabismus (strabismus). In: Werner E. Gerabek , Bernhard D. Haage, Gundolf Keil, Wolfgang Wegner (eds.): Enzyklopädie Medizingeschichte. De Gruyter, Berlin / New York 2005, ISBN 3-11-015714-4 , p. 1295.
- ↑ Elfried Stangler-Aggregate: Squinting in Art ?! - An examination from a medical point of view . Vienna.
- ^ Franz Krogmann: Strabismus (strabismus). 2005, p. 1295.
- ^ Rudolf Sieverts, Hans-Joachim Schneider (ed.): Concise dictionary of criminology - psychology of crime. de Gruyter, 1976, ISBN 3-11-007107-X , p 422 .
- ↑ Meaning of the word in Wiktionary
