Nystagmus Flashcards
What is nystagmus
Involuntary back and forth or cyclical movements of the eyes
*rotatory, horizontal, vertical
When is nystagmus most noticeable
When the patient gazes at objects moving by rapidly or at a fixed object in peripheral fields
What are the different types of jerk nystagmus
- Convergence
- Downbeat
- Vestribular
What is convergence retraction nystagmus
Irregular jerking of the eyes back into the orbit during upward gaze
*may indicate midbrain tegmental damage
What is downbeat nystagmus
The irregular downward jerking of the eyes during downward gaze
*can signal lower medullary damage
What is vestibular nystagmus
The horizontal or rotary movement of the eyes
*suggest vestibular dysfunction
What are the different types of pendular nystagmus
- Horizontal
- Vertical/seesaws
What is horizontal nystagmus
Oscillations of equal velocity around a center point
*indicated congenital loss of visual acuity or multiple sclerosis
What is vertical nystagmus
Rapid seesaw movement of the eyes
*one eye appears to rise while the other appears to fall
*suggest optic chiasm lesion
