Nystagmus is the
rhythmic, involuntary and jerky movements (oscillations) of the eyeball
when they are fixed on an object. Nystagmus signifies the disturbance in ocular
posture.
How to test for nystagmus?
- At first,you should test the power of the extraocular muscles to eliminate their weakness or paralysis because in such that situation, nystagmoid movements will appear.
- Now ask the patient to look forward. Observe for pendular nystagmus
- Fix the head of the patient with the left hand of the examiner
- Ask the patient to look at the examiner’s finger kept at 60 cm away from the patient.
- Now the patient Is asked to fix his vision towards your Index finger which is kept laterally to the
- right side and then to the left side in turn (your finger must be placed within the binocular vision
- of the patient The finger should he in the field of binocular vision, means not > 30° from primary position or the medial limhus of the opposite eye should not cross the punctum of the eyelid on that side.
- Keep it for 5 seconds to detect latent nystagmus. It is the examination of nystagmus in the horizontal plane.
- Next place your finger above and then below his head to examine the nystagmus in the vertical plane.
- Observe nystagmus in both eyes
