Artikel
Bitemporal hemianopia in traffic
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
Text
Objective
Patients suffering from pituitary adenomas and diseases of the chiasma typically show a bitempor hemianopia. Classically, a vertical separation line in the visual field of the injured temporal field of each eye. The residual undisturbed nasal visual field of both eyes have an extension of (at least) 120° and are according to the actual German traffic rules (FeVÄndV) for cars of the classes A, B, M, L und T. The intact half fields fit geometrically to one virtual normal field, that seems to correspond in the center to a normal field. References to this problem often do not address correctly the questions of suitability for traffic.
Methods
The case of a patient with typical bitemporal hemianopia shows the sensorial peculiarities: the functioning temporal retinal halfs are not corresponding. Thus, the alignment of both eyes is not stabilized, resulting often in exo- or esodeviations. Exodeviatios lead to disturbing diplopia, while much better tolerated esodeviations -even of small amount, e.g., 2° - have a vertical scotoma of this extension in the central visual field.
Results
In bitemporal hemianopia the undisturbed nasal visual half fields do not add to a "nearly normal field of one eye". Moreover, either diplopia or - much more dangerous in traffic - a central vertical scotoma is resulting. The peripheral extension of the visual field is not the key problem.
Conclusions
In bitemporal hemianopia there is typically no eligibility for driving a car or motorbike in traffic.