Strabismus sursoadductorius
| Classification according to ICD-10 | |
|---|---|
| H50.2 | Vertical strabismus - hypertropia |
| ICD-10 online (WHO version 2019) | |
As strabismus sursoadductorius is called a descriptive symptoms within the squint medicine ( Strabismus ).
shape
This is understood to mean the squint position of an eye in the form of an increasing height ( hypertropia ) with increased eye movement towards the nose ( adduction ). The extent of the vertical squint deviation remains relatively constant when looking up and down in most cases, so it is concomitant . In some cases, however, an atypical inconsistency pattern is also described. Often a so-called V-symptom is associated with the strabismus sursoadductorius , the increase in a horizontal internal squint angle when looking down or its decrease when looking up. The combination with an external squint is also possible, which means a decrease in the external squint when looking down and its increase when looking up in the case of the V symptom. It is not uncommon for those affected to adopt a compensatory forced head posture . If double images occur, these are always only vertically offset.
In principle, a distinction can be made between disorders with binocular vision , which often only appear as decompensating forms in adulthood due to a decline in the ability to fuse, and disorders without binocular vision as an accompanying symptom of early childhood internal squint.
etiology
The cause of a strabismus sursoadductorius is usually a congenital disorder of the oblique muscles of the eye, i.e. an underfunction of the musculus superior oblique and overfunction of the musculus inferior oblique . In addition, the strabismus sursoadductorius is often found as an accompanying symptom of the so-called congenital squint syndrome . For a long time, scientists were divided on the exact origin of this form of squint. Different scenarios are discussed, ranging from congenital paresis to the possibility of incorrect innervations and forms of hypoplasia .
The latest, in particular MRI-supported, series of examinations show that a special form, the so-called decompensated strabismus sursoadductorius , is, on the one hand, malformations of the superior oblique muscle or its tendon, and, on the other hand, an innervation disorder caused by an absence or at least due to causes significant trochlear nerve damage and is associated with secondary muscular atrophy . This form of the clinical picture belongs to the group of congenital cranial malinervation syndromes. (" Congenital Cranial Dysinnervation Disorders - CCDD"). However, it only makes up a small proportion of all cases of sursoadductor strabismus and is noteworthy as a differential diagnosis to a congenital trochlear palsy .
So far, very little is known about the exact causes of the predominant form of strabismus sursoadductorius, which occurs as a component of congenital squint syndrome. In addition, there is still disagreement about the term "strabismus sursoadductorius" as a quasi descriptive generic term for the etiologically differing clinical pictures, not least because of the different terminology in German and English, where the term congenital musculus obliquus superior palsy ( congenital superior oblique palsy ) Is used. In the meantime, the term is used exclusively to describe the findings "concomitant elevation of an eye in adduction", as long as the pathogenesis is unclear. Otherwise, the term is specified through a diagnosis.
therapy
Since a strabismus sursoadductorius is almost always associated with a horizontal internal squint, this inward squint is usually reduced first during an operative intervention . This generally results in an improvement in the higher stance even in the primary position , which especially occurs in adduction. However, the disorder of the Mm. obliqui also have an effect on the horizontal squint angle when looking up and down, which is why this aspect can make an operation appropriate to the findings necessary. Depending on the extent of the horizontal deviation when looking above or below, a corresponding distribution of the dosage between the two mm. obliqui, if necessary an intervention is carried out on only one of the two muscles. According to the above-mentioned recent findings with regard to the causes of certain forms of strabismus sursoadductorius, the question arises whether an operative intervention on a muscle that is hardly or not at all innervated makes sense in any case.
Differential diagnosis
As a concomitant strabismus form, the strabismus sursoadductorius must be distinguished from an acquired trochlear palsy , which usually shows incomittent strabismus deviations. In addition, in the case of hypertropia, the possibility of dissociated vertical squint should always be considered.
See also
literature
- Herbert Kaufmann : Strabismus . 5th completely revised edition with Heimo Steffen. Georg Thieme Verlag, 2020, ISBN 978-3-13-241330-6 .
Individual evidence
- ↑ Herbert Kaufmann and others: Strabismus. 4th, fundamentally revised and expanded edition. Georg Thieme Verlag, Stuttgart / New York 2012, ISBN 978-3-13-129724-2 .
- ^ A b Gerold H. Kolling: Genesis and mechanics of strabismus sursoadductorius and congenital Brown syndrome. In: orthoptik - pleoptik. 36/2013.
- ↑ JH Kim, JM Hwang: Absence of the trochlear nerve in patients with superior oblique hypoplasia. In: Ophthalmology. (2010); 117, pp. 2208-2013.
- ↑ HK Yang, JH Kim, JM Hwang: Congenital superior oblique palsy and trochlear nerve absence: a clinical and radiological study. In: Ophthalmology. (2012); 119, pp. 170-177.
