This document discusses congenital nystagmus, including its pathophysiology, classification, evaluation, and treatment. There are three main mechanisms that help maintain clear vision: ocular fixation, the vestibulo-ocular reflex, and the central nervous system. Nystagmus is classified based on characteristics like direction, amplitude, frequency, and whether it is conjugate or disjunctive. Evaluation involves assessing visual acuity, eye movements, and neuroimaging in some cases. Treatment may include optical corrections, medications, botulinum toxin injections, or strabismus surgery to modify eye position and reduce nystagmus intensity.

1. Congenital Nystagmus
Dr Sarah Khan

2. PATHOPHYSIOLOGY
• Three main mechanisms are involved in
maintenance of the image of the target of
interest on the fovea
• Ocular fixation
• Vestibulo ocular reflex
• Central nervous system as the neural
integrator

3. • Ocular fixation helps to keep the drifting
image of the object on the fovea and also
suppresses any unwanted saccades

4. • Vestibulo ocular fixation helps to maintain a
good visual acuity by keeping the eye
movements compensated for changes in the
head posture during various routine activities

5. • The neural integrator helps to maintain the
eye position in an eccentric position during
different gazes against the pull of suspensory
ligaments and the EOM that tend to bring the
eye back to the central position

6. • NULL POSITION :
• Position of gaze in which the nystagmus is
minimally ellicited. To keep the eye in this
position, the child may adopt a face turn or a
chin elevation or depression depending on the
null position. This enables the child to keep
the image of the target at the fovea for a
longer time to enable a clear visual acuity (
Foveation period)

7. • PENDULAR NYSTAGMUS has a sinusoidal
pattern without differentiation into a slow or
fast component

8. • NEUTRAL ZONE : This is observed in Periodic
alternating nystgamus in which the fast
component changes direction after an interval
of time

9. • CONJUGATE NYSTAGMUS : Nystagmus in the
two eyes is similar in amplitude, frequency
and direction
• DISCONJUGATE NYSTAGMUS : The direction
of nystagmus in the two eyes is different
• DISSOCIATED NYSTAGMUS : The amplitude of
the nystagmus is different but the direction
remains the same

10. • JERK NYSTAGMUS has a slow and a fast component and
is named based on the fast component
• Direction of the nystagmus is the direction of its fast
component
• Plane could be horizontal, vertical or rotator or a
combination of these
• Amplitude is the excursion of the nystagmus which
maybe small(<5deg), moderate (5-15deg) and large(
>15deg)
• Frequency Number of beats per second, slow (1-2Hz) ,
medium (3-4Hz), Fast (>5Hz)
• Intensity = Amplitude * Frequency

11. Classification of Nystagmus
• CEMAS : Classification of Eye Movement
Abnormalities and Strabismus
• By the National Eye Institute
A CLASSIFICATION OF EYE MOVEMENT ABNORMALITIES AND STRABISMUS (CEMAS) Report of a National Eye Institute Sponsored
Workshop , Richard W. Hertle, NEI

12. NYSTAGMUS AND OCULAR MOTOR
OSCILLATIONS
• A. PHYSIOLOGICAL FIXATIONAL MOVEMENTS
1. MICROTREMOR
2. SLOW DRIFTS
3. MICROSACCADES
A CLASSIFICATION OF EYE MOVEMENT ABNORMALITIES AND STRABISMUS (CEMAS) Report of a National Eye Institute Sponsored
Workshop , Richard W. Hertle, NEI

13. • B. PHYSIOLOGICAL NYSTAGMUS
1. VESTIBULAR
2. OPTOKINETIC
3. ECCENTRIC GAZE NYSTAGMUS
A CLASSIFICATION OF EYE MOVEMENT ABNORMALITIES AND STRABISMUS (CEMAS) Report of a National Eye Institute Sponsored
Workshop , Richard W. Hertle, NEI

14. • C. PATHOLOGICAL NYSTAGMUS
1. INFANTILE NYSTAGMUS SYNDROME (INS)
2. FUSION MAL DEVELOPMENT NYSTAGMU
SYNDROME (FMNS)
3. SPASMUS NUTANS SYNDROME
4. VESTIBULAR NYSTAGMUS
a. PERIPHERAL VESTIBULAR IMBALANCE
b. CENTRAL VESTIBULAR IMBALANCE
c. CENTRAL VESTIBULAR INSTABILITY (PAN)
A CLASSIFICATION OF EYE MOVEMENT ABNORMALITIES AND STRABISMUS (CEMAS) Report of a National Eye Institute Sponsored
Workshop , Richard W. Hertle, NEI

15. 5. GAZE HOLDING DEFICIENCY NYSTAGMUS
a. ECCENTRIC GAZE NYSTAGMUS ( AND ASSOCIATED
REBOUND NYSTAGMUS)
b. GAZE INSTABILITY NYSTAGMUS
6. VISION LOSS NYSTAGMUS
a. PRECHIASMAL
b. CHIASMAL
c. POSTCHIASMAL
A CLASSIFICATION OF EYE MOVEMENT ABNORMALITIES AND STRABISMUS (CEMAS) Report of a National Eye Institute Sponsored
Workshop , Richard W. Hertle, NEI

16. 7. OTHER PENDULAR NYSTAGMUS AND
NYSTAGMUS ASSOCIATED WITH DISEASE OF
CENTRAL MYELIN
a. MS, PELIAZAEUS MERZBACHER DISEASE,
COCKAYNE’S PEROXISOMAL DISORDERS,
TOLUENE ABUSE
b. PENDULAR NYSTAGMUS ASSOCIATED WITH
TREMOR OF THE PALATE
c. PENDULAR VERGENCE NYSTAGMUS ASSOCIATED
WITH WHIPLE’S DISEASE
A CLASSIFICATION OF EYE MOVEMENT ABNORMALITIES AND STRABISMUS (CEMAS) Report of a National Eye Institute Sponsored
Workshop , Richard W. Hertle, NEI

17. 8. OCULAR BOBBING (TYPICAL AND ATYPICAL)
9. LID NYSTAGMUS
A CLASSIFICATION OF EYE MOVEMENT ABNORMALITIES AND STRABISMUS (CEMAS) Report of a National Eye Institute Sponsored
Workshop , Richard W. Hertle, NEI

18. D. Saccadic intrusions and oscillations
• Square wave jerks and oscillations
• Square wave pulses
• Saccadic pulses
• Induced convergence retraction
• Dissociated ocular oscillations
• Hypermetric saccades
• Macrosaccadic oscillations
• Ocular flutter
• Flutter dysmetria
• Opsoclonus
• Psychogenic flutter
• Superior oblique myokymia

19. E. Generalised disturbance of saccades
F. Generalised disturbance of smooth pursuit
G. Generalised disturbance of vestibular eye
movements
H. Generalised disturbance of optokinetic eye
movements

20. INFANTILE NYSTAGMUS SYNDROME
• Appears by 0-6 months of age
• Progresses from pendular to jerk type
• Conjugate, uniplanar, horizontal
• Stabilises at 5-6 years of age
• Accelerating slow phase
• Increases on attempt to fixate
• Decreases with convergence
• Marked head posture

21. • Strong family predisposition
• Abolished during sleep
• May have a latent component
• May show reversal pattern with OKN

23. Fusion maldevelopment nystagmus
syndrome
• FMNS has an infantile onset
• Conjugate, horizontal and uniplanar
• May appear or increase in mono ocular
fixation
• Linear decelerating slow phase with fast phase
in the direction of the uncovered fixing eye
• Reverses direction with change in fixation
• Intensity decreases with age

24. Spasmus nutans syndrome
• Constellation of ocular oscillation , head
bobbing and torticollis
• Appears at 4-18 months of age and disappears
by 3 years of age
• Nystagmus increases with convergence
• MRI/CT are normal

26. Periodic alternating Nystagmus
• This is a central vestibular instability
nystagmus.
• It exhibits a neutral point with a jerk
nystagmus in one direction for 60-90 seconds
which then changes to the other direction for
another 60-90 second

27. • It, therefore needs to be observed for atleast 3
minutes. It is not affected by visual fixation
• It can be acquired or it maybe a part of the
infantile nystagmus syndrome exhibiting an
accelerating slow phase in the ocular motor
recordings

28. video

29. Evaluation
• A good clinical history
• Ante natal history
• Birth history
• Age of onset, associated decreased vision
• Acute onset, diplopia, oscillopsia point
towards acquired causes

30. • Family history
• Maternal drug intake ante natally
• Or perinatal infections

31. Examination
• Visual acuity
• Uniocular and binocular
• Near and distance
• With and without head posture

32. • A complete ocular examination of the anterior
and posterior segments

34. • Measurement of any face turn
• Goniometer or a protractor
• Helps to decide the amount of surgical
correction required

36. • Video recording of the ocular movements
• And if available ocular movement tracing

37. • Neuro imaging is required in cases of
 All acquired nystagmus
 Periodic alternating nystagmus
 Seesaw nytagmus
 Spasms nutans syndrome
 INS with poor vision and disc pallor

38. Electrooculography

41. Infrared oculography

42. • Binocular infrared oculography BIRO
• Video oculography which traces ocular
movements using infra red techniques

44. • Electromagnetic search coil method
• Scleral contact lenses are worn

45. Scleral search coils

46. ICS ChartR VNG

47. Drug treatments
• Anticholinergics, anti histaminics
• Acetazoleamide effective in familial periodic
ataxia with nystagmus
• Baclofen decreases symptoms in PAN (
increases the inhibitory effect of GABA on the
vestibular nuclei)
• Botulinum toxin injections

48. Optical treatment
• In congenital nystagmus, convergence and
eccentric gaze decreases nystagmus
• To induce convergence , 7D base out prism
can be placed in each spectacle lens
• In young patients -1.00 D can be added to the
spectacle correction

49. • If null zone is in a horizontal eccentric gaze,
prism apices pointing towards the null zone
may help
• Contact lenses correct refractive errors more
effectively , and the tactile sensory feedback
might decrease the intensity of nystagmus

50. Surgery
• To shift the null position from eccentric
position to primary position
• Increase foveation
• To reduce a an abnormal head position

51. NYSTAGMUS +++
INTENSITY OF NYSTAGMUS REDUCED IN LEVOVERSION
NYSTAGMUS +
HENCE PATIENT HAS A FACE
TURN TO THE RIGHT

52. It may be good to wait till 4-5 yrs to allow for
maturation of binocular visual system

53. To correct the head posture
• Anderson’s surgery : Weakening the yoke
muscles responsible for the slow phase of
nystagmus

54. • Kestenbaum’s procedure : 5mm resection
recession of all four horizontal recti to move
the null position to the primary position

55. • Goto’s surgery : Resection of the recti that
move the eye away from the null position

56. • Modified Park’s Kestenbaum procedure :
Recession of one MR 5mm, and LR 7mm
And resection of other MR 6mm and LR 8mm

57. • Augmented modified Kestenbaum’s :
If the head turn is up to 30 degree,
The values of recessions and resections can be
increased by 40%

58. • Spielmann’s Procedure : in head turn more
than 20 degree, Kestenbaum’s procedure with
posterior fixation sutures on the recessed
muscle

59. • Pratt Johnson’s surgrery : Equal recession and
resection of all horizontal recti

60. • Chin elevation : Recession of inferior rectus
which can be combined with resection of
superior rectus
• And vice versa for chin depression

61. • Head tilt : Vertical shift of horizontal recti or
horizontal shift of vertical recti

62. • If there is no null position, or null position is in
the primary position
• Aim of surgery in nystagmus is to dampen the
intensity of nystagmus

63. • Surgically induced exotropia
• Large recession of all horizontal recti

64. THANK YOU