Nystagmus is involuntary, rhythmic eye movement that can be either physiological or pathological. It is classified based on its mechanism, direction, frequency and other characteristics. Common types include infantile nystagmus, acquired nystagmus, upbeat nystagmus, and downbeat nystagmus. Nystagmus is evaluated through history, eye examination, neuroimaging and eye movement recordings. Treatment aims to improve vision and reduce oscillopsia, using optical, medical or surgical methods like prisms, medications, and extraocular muscle surgery.

1. By – Praneet Mishra
Boptometry student at Nshm Dugrapur

2. Nystagmus

3. Nystagmus
Terms
01
Table of contents
Mechanism
02
03
Symptoms
04
05 Classification
06
07
08
Evaluation
Treatment
Reference

4. 01 INTRODUCTION

5. Introduction
Nystagmus is involuntary, rhythmic, oscillatory to and fro movement of eye

6. 2 TERMS

7. Pendular
phases of equal velocity
• Horizontal • Vertical • Rotatory • Oblique

8. Jerk
Phases of unequal velocity
It has slow and fast component
Direction – direction of fast component Pathological movement is slow
one

9. Conjugate , Disconjugate
Conjugate – both eyes same movement

10. Frequency
Frequency is the number of to and fro movements in one second.
Described an cycles/sec or Hertz(Hz)
Slow : 1-2Hz
Medium : 3-4Hz
Fast : 5Hz or more

11. Null Zone/Point
Gaze in which intensity is minimum

12. 3 MECHANISM

13. Steady gaze Mechanism
1. 1. Fixation : detect retinal image drift
and initiate corrective eye movements
2. 2. Vestibulo-ocular reflex ( VOR ) : eye
movements compensate for head rotations
ensuring clear vision during locomotion
3. 3. Oculomotor Neural integrators :
muscle activity to counteract pull of
extraocular muscles.
A nystagmus is caused by defect in any of above mechanisms or their
adaptive tuning.

14. 4 Symptoms

15. Symptoms of nystagmus
• 1. Blurred vision
• 2. Oscillopsia : illusion that the stationary world is moving.
• 3. Vertigo, dizziness, loss of balance ( vestibular )

16. 5 Classification

17. Nystagmus
Physiological
End gaze
Optokinetic
Vestibulo-ocular
reflex
Pathological
Early Onset
Infantile
nystagmus
Fusional
maldevelopment
Spasmus nutans
syndrome
Acquired
Up,beat
,downbeat
See saw
Etc.

18. Physiological
Nystagmus

19. ● Nystagmus stimulated when watching a moving object
OPTOKINETIC NYSTAGMUS ( OKN )

20. OPTOKINETIC NYSTAGMUS

21. ● It is a transient fine jerk horizontal nystagmus seen in normal
persons on extreme right or left gaze.
End Point Nystagmus

22. ● It is a jerk nystagmus which can be elicited by stimulating the tympanic
membrane ( ear drum ) with hot or cold water. It forms the basis of caloric
test.
● Cold water produces horizontal nystagmus with fast phase away from tested
ear
● If cold water is poured into right ear, the patient develops left jerk
nystagmus (rapid phase towards left) while the reverse happens with warm
water, i.e. patient develops right jerk nystagmus.
Used to differentiate central vs peripheral vestibular lesions, absent response
means peripheral vestibular dysfunction
Physiological vestibular nystagmus / Caloric
Nystagmus

23. Caloric Nystagmus Testing

24. Pathological
Nystagmus

25. A. EARLY ONSET
( CHILDHOOD
NYSTAGMUS )

26. The three most common forms of nystagmus seen in childhood begin in
infancy and are, therefore, not congenital. These include:
1. Infantile nystagmus syndrome
2. Fusion maldevelopment nystagmus syndrome
3. Spasmus nutans syndrome
A. EARLY ONSET ( CHILDHOOD
NYSTAGMUS )

27. • Due to a congenital anomaly of motor system or to a congenital
disorder of vision
• Usually not noticed at birth but becomes apparent during first few
months of life.
1. Infantile Nystagmus Syndrome
( Congenital Nystagmus )

28. Etiology :
• Retinal diseases, such as retinoblastism, retinopathy of prematurity
(ROP), persistant hyperplastic primary vitreous (PHPV)
• Ocular albinism, characterized by iris transillumination defects and
foveal hypoplasia.
• Aniridia, i.e. bilateral near total congenital iris absence.
• Other causes include, bilateral congenital cataract, achromatopsia,
congenital stationary night blindness, bilateral optic nerve hypoplasia.
1. Infantile Nystagmus Syndrome
( Congenital Nystagmus )

29. Characteristics
• Conjugate, horizontal-torsional, increases with fixation attempt
• Progression from pendular to jerk
• Family history often positive •
• With or without normal visual acuity or refractive error
• Null and neutral zones present
• Associated latent nystagmus
• Head turn to achieve null point
• Decreases with convergence
• Increase with fixation
1. Infantile Nystagmus Syndrome
( Congenital Nystagmus )

30. 1. Infantile Nystagmus Syndrome
( Congenital Nystagmus )

31. 2. Fusional maldevelopment nystagmus
syndrome
• Fusion maldevelopment nystagmus syndrome (FMNS) is the new name
for the old term— latent/latent manifest nystagmus
Characteristics
CEMAS criteria for FMNS are summarized below:
• Infantile onset
• High frequency, low-amplitude pendular nystagmus (dual-jerk
waveform), jerk in direction of fixing eye
• Intensity decreases with age.
• Ocular motor recordings show two types of slow phases linear and
decelerating.
• Nystagmus is not present, when both eyes are open.

32. 2. Fusional maldevelopment nystagmus
syndrome
Characteristics
• It appears when one eye is covered. It is a jerk nystagmus with rapid
phase towards the uncovered eye.
• • Becomes manifest under monocular viewing conditions, i.e. in the
presence of decreased vision in one eye as in anisometropic
amblyopia, strabismic amblyopia, etc.

33. 2. Fusional maldevelopment nystagmus
syndrome

34. 3.Spasmus nutans syndrome
• Spasmus nutans syndrome (SNS), old name spasmus nutans (SN) is
the 3rd most common nystagmus seen in infancy. Characteristic
features CEMAS
Characteristics
CEMAS criteria for SNS are as below:
• Infantile onset •, small-frequency, low amplitude oscillation
• Abnormal head posture and head oscillation, improves (disappears)
during childhood
• Normal MRI/CT scan of visual pathways
• Ocular motility recordings—high-frequency (>10 Hz), asymmetric,,
pendular oscillations

35. 3.Spasmus nutans syndrome

36. B. Acquired
Nystagmus

37. 1. Nystagmus associated with diseases of
visual system
• Vertical nystagmus
• See-saw nystagmus
• Acquired pendular nystagmus

38. Vertical nystagmus
It is seen in vertical nystagmus disease affecting the optic nerves.
Optic nerve disease is associated with vertical pendular nystagmus.
The nystagmus has vertical, low frequency, bidirectional drifts
(pendular), unidirectional horizontal drifts with corrective quick-phases
(jerk) are less common.
When disease affects both optic nerves, the amplitude of nystagmus is
greater in the eye with poorer vision.

39. Vertical nystagmus

40. Upbeat nystagmus
• Type of jerk nystagmus with fast phase upward in primary position
• Often worsens in upgaze
• Causes :
Lesions of medulla
Cerebellar vermis,
• Base up prisms in reading glasses can be used to force the eye
downward.

41. Upbeat nystagmus

42. Downbeat nystagmus
• Type of jerk nystagmus with fast phase downward in primary position
• Often worsens in downgaze
• Oscillopsia is usually prominent
• Causes :
lesions at cervicomedullary junction,
• Base down prisms in reading glasses can be used to force the eye
upward.

43. Downbeat nystagmus

44. Seesaw nystagmus
• Defined as pendular nystagmus with elevation and intorsion of one eye
simultaneous with depression and extorsion of the eye
• Followed by reversal of cycle, so that the eyes move like a seesaw
• Causes : parasellar lesions, pituitary tumors
• Produces very disabling oscillopsia that responds poorly to any Rx

45. Seesaw nystagmus

46. 6
CLINICAL
EVALUATION &
PHYSIOLOGICAL
RECORDING AND
NEUROIMAGING

47. A. Clinical Evaluation

48. History
History should include:
• Duration of nystagmus
• Whether it interferes with vision and causes oscillopsia
• Accompanying neurological symptoms
• Whether nystagmus and other visual symptoms are worse with viewing
far or near objects, or with patient motion, or with different gaze
angles.
• If abnormal head posture is present, whether or not these features
are evident on old photographs.

49. Examination of a patient with nystagmus
Comprehensive examination of the visual system
• Visual acuity assessment
• Anterior and posture segment examination
• Measurement of head posture.

50. B.
ELECTROPHYSIOLOGICAL
RECORDING OF EYE
MOVEMENTS

51. Examination of a patient with nystagmus
Techniques available for ocular motility recordings are :
• Electro-oculography

52. Examination of a patient with nystagmus
• Electronystagmography

53. Examination of a patient with nystagmus
Binocular infrared reflectance oculography ( BIRO )

54. Examination of a patient with nystagmus
Electromagnetic scleral search coil method

55. Examination of a patient with nystagmus
videonystagmography

56. C. Neuroimaging

57. Neuroimaging
Neuroimaging is indicated to find out associated CNS abnormalities
especially in patients with acquired nystagmus, periodic alternating
nystagmus, see saw nystagmus, spasmus nutans syndrome and infantile
nystagmus syndrome with pallor disc and poor vision.

58. 7 Treatment

59. Aim of Treatment
• To improve visual acuity by stabilizing the eyes
• To shift the null zone, if any, in the primary position, i.e. to reduce
abnormal head posture.
• To correct the associated strabismus
• To decrease any oscillopsia wherever possible.

60. Treatment modalities
Treatment modalities for nystagmus include:
• Optical
• Medical
• Surgical.

61. Optical Treatment
Glasses : overminus lenses stimulate accommodative convergence
and thus dampens nystagmus
Prisms :
i. Base-out prisms may stimulate fusional convergence (especially
in patients with congenital motor nystagmus) and thus improve the
visual acuity by dampening the nystagmus.
ii. Prisms with base opposite to preferred direction of gaze may
be helpful in correcting the head posture. Prisms minimize a head
turn by reorienting the visual axis towards primary gaze. Often
. .

62. Medical Treatment
• cyclopentolate : reduce the amplitude, velocity and frequency of latent
nystagmus in about 60% of the patient
• botulinum toxin : dampen nystagmus and improve visual acuity in
patient with acquired nystagmus and oscillopsia
• baclofen : suppress the acquired periodic alternating nystagmus
•clonazepam : may be useful in patient with downbeat nystagmus and
see-saw nystagmus

63. Surgical Treatment
• kestenbaum surgery
•Anderson surgery
•Parks surgery

64. 8 Reference

65. Reference
• Ak khurana, Theory and practice of squint and orthoptics Third Edition
eBook : 2018.
• Jack J Kanski.Kanski’s, Clinical Ophthalmology Ninth Edition : 2020
• Leonard A. Levin, Ocular Disease: Mechanisms and Management First
Edition : 2010
● Dr. Shashwat ray lecture
Videos :
● Neurozone Videos Youtube
● Moran core Youtube
● Michigan medicine youtube