Scotoma

Under scotoma (from Greek Skotos "darkness" ) is understood in ophthalmology a portion of the visual field, the sensitivity is reduced. With complete sensory loss ( blindness ) for this subregion is called an absolute, with only partial sensory loss of a relative scotoma.

Physiological (not pathological ), absolute scotomas are eg the blind spot and the annular scotoma, the positive diopter values ​​occurs by the magnification effect on the edge of the glass for spectacle lenses.

Pathological ( abnormal ) scotomata may occur due to a disease of the retina, the optic tract or visual cortex. For example, a vascular occlusion in a blood vessel supplying the optic nerve lead to irreparable scotoma due to failure of nerve fiber bundles. Temporary scotomas like the scintillating scotoma, for example as part of a migraine can occur suddenly; they are formed mostly within a relatively short time completely back.

An outgoing from the blind spot, typical arcuate visual field loss in glaucoma is called Bjerrum scotoma.

A central scotoma or Fixierpunktskotom without organic cause occurs with eccentric fixation usually on the squinting eye on, as long as the other, central fixing eye is open. This prevents the otherwise occurring double vision ( diplopia or confusion ). Once the leading eye is closed, this is a functional scotoma of the squinting eye is no longer detectable.

Flimmerskotom

Affected portray a perception of bright, flickering or kaleidoscope rotating light in a most eccentric park of the visual field, which initially expands, but does not cover the entire field. The occurrence happens suddenly. The data subject may at first have the feeling that you have seen in a strong light source, because the experience of a scintillating scotoma a glare can be similar. As with a glare may no longer be possible the direct fixing of objects or text. If only part of the visual field is affected by the failure, an orientation in space is quite possible.

A scintillating scotoma can - especially when it occurs in the context of migraine - be accompanied by nausea, vomiting and headache, often it occurs but without these side effects on. Also, the simultaneous occurrence of high light sensitivity and other hypersensitivity occurs.

The occurrence of a scintillating scotoma is temporary. Mostly, its duration is limited to about 20 to 30 minutes.

Sets a scintillating scotoma one while driving, you should go as soon as possible to the curb and wait for the end of the scotoma.

The cause of the scintillating scotoma is unknown. Because of the very similar perceptions of many migraine patients suspected a similar formation mechanism as in migraine. However occurred scintillating scotoma without migraine usually on time for several months confined to. Scintillating scotoma without migraine usually require no treatment.