Hemianopia
| Classification according to ICD-10 | |
|---|---|
| H53.4 | Visual field defects - heteronymous hemianopia - homonymous hemianopia |
| ICD-10 online (WHO version 2019) | |
As hemianopia or hemianopia (from . Greek hemi "half", a "no" and ops "see" - Synonym: half page blindness ) is a frequently limited by the vertical axis, unilateral visual field defect called the usually bilateral, rarely, however, only one side occurs.
A distinction is made between failures on both sides
- Homonymous hemianopia (right or left): The same side is affected by the failure in both eyes (for example, patients can only see the left or right area of an image section).
- heteronymous (usually bitemporal) hemianopia: the opposite side of both eyes is affected by the failure (for example, patients suffer from a “blinkered look”). This occurs when there is damage to the junction of the optic nerve and is usually bitemporal when something from the middle presses on the two nerves. A bilateral compression from the outside can lead to a binasal hemianopia, but has been observed very rarely and so far not symmetrically, as shown in the picture.
The cause is a lesion in the course of the visual pathway . The type of hemianopia allows conclusions to be drawn about the location of the disorder. If this is just in front of the optic chiasm , the visual field loss can occur on one side, otherwise on both sides. They are named according to the direction of the loss of visual field. A temporal (lateral) visual field defect, for example, means the failure of the nasal (facing the nose) retinal halves of the eye, because the nasal retinal areas are located temporally and vice versa. About 10% of hemianopsies only affect the upper or lower quadrants of the visual field . In addition, hemianopsias can be associated with a central, macular recess. Their detection is difficult because of their usually small size (about 1 °), but their significance for the identification of occipital causes is considerable.
The visual neglect , in which there is a disruption of attention to one side, must be distinguished from hemianopia . Affected patients usually experience this form of neglect due to damage to the brain on the opposite side. The visual pathway does not have to be directly affected by the lesion.
See also
literature
- Rudolf Sachsenweger: Neuroophthalmology . Thieme Verlag, Stuttgart; 3rd edition, (January 1983), ISBN 978-3-13-531003-9 .
Individual evidence
- ↑ Wolfgang Straub: About the binasal hemianopia . In: Acta Ophthalmologica . 30, No. 2, 1952, ISSN 1755-3768 , pp. 229-252. doi : 10.1111 / j.1755-3768.1952.tb07656.x .
- ↑ Dr Georg Vlavianos: About binasal hemianopia . In: Archives for Psychiatry and Nervous Diseases . 97, No. 1, December 1, 1932, ISSN 0003-9373 , pp. 207-220. doi : 10.1007 / BF01815542 .
- ^ Dieter Schmidt: Hemianopsia, monocular temporal. In: Dieter Schmidt: Tips and tricks for the ophthalmologist. Problem solutions from A - Z. Springer Medicine, Heidelberg 2008, ISBN 978-3-540-48717-3 , pp. 192–193, doi : 10.1007 / 978-3-540-48718-0_77 .
- ^ Hans-Henning von Albert: From the neurological symptom to the diagnosis. Differential diagnostic master programs. 5th edition. Springer, Berlin et al. 2002, ISBN 3-540-41811-3 , p. 114.
- ^ Theodor Axenfeld (founder), Hans Pau (ed.): Textbook and atlas of ophthalmology. With the collaboration of Rudolf Sachsenweger and others 12th, completely revised edition. Gustav Fischer, Stuttgart et al. 1980, ISBN 3-437-00255-4 , p. 418.
