Diese Präsentation wurde erfolgreich gemeldet.
Wir verwenden Ihre LinkedIn Profilangaben und Informationen zu Ihren Aktivitäten, um Anzeigen zu personalisieren und Ihnen relevantere Inhalte anzuzeigen. Sie können Ihre Anzeigeneinstellungen jederzeit ändern.
Nystagmus and 
Spontaneous eye 
movement disorders 
DR. NAMRATA GUPTA
Definition 
Fixation instabilities that are involuntary and 
rhythmic 
 Nystagmus- inability to maintain fixation due to ...
Background 
 Foveal centration of an object of regard is necessary to 
obtain the highest level of visual acuity 
 Three...
Fixation 
 Involves the visual system's ability to detect drift 
of a foveating image 
 Signal an appropriate corrective...
Vestibulo-ocular reflex
Neural integrator 
 A gaze- holding network : Complex integration 
between cortical centers, cerebellum, ascending 
vesti...
 When the eye is turned in an extreme position in 
the orbit, the fascia and ligaments that suspend 
the eye exert an ela...
Failure of control system- disruption of steady fixation 
A. Nystagmus 
B. Saccadic intrusion or saccadic oscillations
Nystagmus 
 Nystagmus is a repetitive, involuntary to and fro 
movement of the eyes (horizontal, vertical or 
torsional) ...
Terminologies 
• Saccade/ Pursuit 
• Jerk / Pendular 
• Null zone 
• Amplitude 
• Frequency 
• Intensity 
• Conjugate / Di...
Saccade/ Pursuit 
 Saccades are sudden, simultaneous movements of 
both eyes in the same direction to place the object 
o...
Jerk / Pendular 
Jerk nystagmus Pendular nystagmus 
Alternation of slow defoveating 
drift and rapid corrective 
saccade i...
Pendular nystagmus 
Jerk nystagmus
Amplitude 
 Amplitude is the excursion of the nystagmus 
 Fine : less than 50 
 Medium : 50-150 
 Coarse : greater tha...
Frequency 
 Frequency is the number of to and fro movements 
in one second 
 Described an cycles/sec or Hertz (Hz) 
 Sl...
Intensity 
 Intensity = amplitude x frequency 
 Null zone: position where intensity of nystagmus is 
minimized, foveatio...
Conjugate/Dissociated 
 Conjugate : Nystagmus which is symmetric in 
direction, amplitude and rate between two eyes 
 Di...
Schematic for Nystagmus
Nystagmus 
waveforms
Alexanders law 
 It states that the amplitude of jerk nystagmus is 
largest in the gaze of direction of fast component 
...
Classification 
• Optokinetic 
• Vestibular 
• End-point 
Physiological 
• Congenital nystagmus 
• latent nystagmus 
• Spa...
Physiological 
 End point nystagmus 
 Vestibular (caloric or rotational) nystagmus 
 Optokinetic nystagmus
End point nystagmus 
 Jerk nystagmus 
 On looking extreme lateral or upwards 
 Small amplitude <20 and Angle of gaze > ...
Vestibular nystagmus 
 Jerk nystagmus due to 
altered inputs from 
vestibular nuclei to PPRF 
physiological
Vestibular nystagmus 
Types: 
 Rotatory vestibular nystagmus- stimulation of 
vestibular labyrinth or nerve secondary to ...
physiological 
Optokinetic nystagmus 
 Jerk nystagmus 
 Induced by moving a full visual field stimulus 
 Slow phase (pu...
Early onset (childhood) 
 Congenital nystagmus 
 Latent nystagmus 
 Spasmus nutans
Congenital nystagmus 
(Infantile nystagmus syndrome) 
 80% of all nystagmus 
 Usually not noted at birth , apparent duri...
Characteristics 
Congenital nystagmus 
 Horizontal nystagmus ( mixed pendular and jerk) 
 Bilateral conjugate movements ...
 Reverse response to OKN stimulus ( fast phase in 
direction of moving OKN drum) 
 Exponential increase in velocity of s...
Treatment 
 Base out prisms to induce convergence 
(dampens the nystagmus and may improve visual 
acuity) 
 Use of prism...
Surgical 
Congenital nystagmus 
 Includes moving the extraocular muscles to place 
the null zone in primary position(kest...
Latent nystagmus 
(Fusional maldevelopment nystagmus 
syndrome) 
 Conjugate jerk nystagmus 
 Beginning or accentuation w...
Spasmus nutans 
Triad of symptoms: 
 Pendular Nystagmus 
 Head nodding 
 Torticollis (head tilt or head turn)
Spasmus nutans 
 Onset usually in the first year of life (3-15 months) 
 Disappears by 3-4 yrs of age 
 Intermittent , ...
Infantile monocular pendular 
nystagmus 
 Monocular vertical or elliptical high frequency 
nystagmus 
 Heimann-Bielchows...
Acquired nystagmus 
Nystagmus associated 
with poor vision (sensory) 
 Anterior segment: 
cataract, aniridia 
 Retinal d...
Gaze paretic nystagmus 
 Most common type 
 Jerk nystagmus at 30° of fixation 
 Fast phase in direction of eccentric ta...
Gaze paretic nystagmus 
 Dysfunction of neural integrator- nucleus prepositus 
hypoglossi and medial vestibular nucleus 
...
Gaze paretic nystagmus
Vestibular nystagmus 
Feature Peripheral Central 
Disease of vestibular origin 
Rotary nystagmus 
Disease of the brainstem...
Upbeat nystagmus 
 Type of jerk nystagmus with fast phase upward in 
primary position 
 Often worsens in upgaze 
 Cause...
Upbeat nystagmus
Downbeat nystagmus 
 Type of jerk nystagmus with fast phase downward in 
primary position 
 Often worsens in downgaze(co...
Downbeat nystagmus
Periodic alternating 
nystagmus (PAN) 
 A repetitive cycling of right beating and left 
beating nystagmus in primary gaze...
Periodic alternating nystagmus 
 Periodic alternating head turn towards fast 
component to minimise nystagmus & oscillops...
Periodic alternating nystagmus
Dissociated Nystagmus 
Difference between two eyes in amplitude of ocular 
oscillations 
A. Acqiured pendular nystagmus in...
Dissociated Nystagmus 
B. Monocular or bilateral vision loss 
1. Monocular - 
• Children: High frequency pendular nystagmu...
Dissociated Nystagmus 
C. Seesaw nystagmus: 
 Disconjugate vertical pendular nystagmus 
 Elevation and intorsion of one ...
Seesaw nystagmus 
 Causes: 
 Parasellar lesions, pituitary tumors 
 Less common- head trauma, brain stem infarction 
 ...
Dissociated Nystagmus 
D. Inter nuclear 
ophthalmoplegia 
 Lesion of medial longitudinal 
fibers 
 Isolated slowing of 
...
Convergence-retraction 
nystagmus 
 Not truly a nystagmus 
 b/l adducting saccades causing convergence of 
both eyes 
 ...
Convergence-retraction nystagmus
Nystagmus associated 
with strabismus 
 Manifest-latent nystagmus 
 Manifest nystagmus 
 Nystagmus blockage syndrome
Manifest nystagmus Manifest-latent nystagmus 
Pendular nystagmus Jerk nystagmus 
No change on abduction Increased on abduc...
Nystagmus blockage 
syndrome 
 Inverse relationship with esotropia 
 Esotropia is a mechanism of blocking the 
nystagmus...
Nystagmoid conditions 
• Reflex saccades to objects in visual field is inhibited by 
pathways from frontal lobe to basal g...
Saccadic intrusion with normal inter-saccadic 
interval 
Square wave kerks 
Macro- square wave kerks 
Macrosaccadic oscill...
Saccadic intrusion without normal 
inter-saccadic interval 
 Ocular flutter- Burst of small amplitude, high 
frequency, h...
Saccadic intrusion without normal inter-saccadic interval 
Ocular flutter/Opsoconus 
Etiology – 
• Unknown in healthy indi...
Ocular bobbing 
 Characterized by rapid downward movement of 
both eyes 
 Followed by slow drift back to midline 
 Caus...
Superior oblique myokymia 
 Defined as high frequency oblique oscillation of one 
eye due to intermittent firing of the s...
Superior oblique myokymia 
 Usually benign 
 No underlying etiology is found 
 Neuroimaging : r/o post fossa tumors 
 ...
Treatment 
Nonsurgical : non neurological causes 
 Optical devices 
• Glasses: High minus lenses stimulate accommodative ...
Nonsurgical : non neurological causes 
 Prisms : 
1. To induce fusional convergence by using 7 PD base 
out prism in fron...
Nonsurgical : non neurological causes 
Occlusion therapy: 
 Trials with conventional occlusion have been found 
to be eff...
Pharmacologic management 
 The drugs hypothetically inhibit excitatory 
neurotransmitters within CNS 
1. Baclofen (GABAB ...
Pharmacologic 
denervation 
 Botulinum toxin A act by blocking the 
neuromuscular transmission 
• 3 units of toxin is inj...
Surgical 
Based on 2 principles: 
 To shift the null position if any to the primary position 
 To reduce the amplitude o...
Kestenbaum surgery 
 Devised first surgical approach using recession-resection 
of all four horizontal recti 
 Advocated...
Anderson surgery 
 Advocated only recessions 
 Left face turn (null in dextroversion): 
 Right eye : LR recession 
 Le...
Parks surgery 
 Recommended lesser amount of recessions and 
resections for medial rectus surgery compared to 
lateral re...
Summary 
 Nystagmus- Slow defoveating drift followed by rapid 
corrective saccade eye movement 
 Physiological, childhoo...
Bibliography 
 American Academy of Ophthalmology. Neuro- 
Ophthalmology. Section 5. 2013-2014 
 Kanski Jack J. Clinical ...
Thank you
Nächste SlideShare
Wird geladen in …5
×

Nystagmus namrata

4.624 Aufrufe

Veröffentlicht am

gave me Nystagmus- Neuro-ophthalmology, physiological and pathological nystagmus

Veröffentlicht in: Gesundheit & Medizin
  • Als Erste(r) kommentieren

Nystagmus namrata

  1. 1. Nystagmus and Spontaneous eye movement disorders DR. NAMRATA GUPTA
  2. 2. Definition Fixation instabilities that are involuntary and rhythmic  Nystagmus- inability to maintain fixation due to slow drift away from fixation followed by rapid corrective eye movement  Saccadic intrusion and saccadic oscillations result from spontaneous rapid eye movement without slow phase
  3. 3. Background  Foveal centration of an object of regard is necessary to obtain the highest level of visual acuity  Three main control mechanisms maintain steady gaze— • Fixation • The vestibulo-ocular reflex • The neural integrator
  4. 4. Fixation  Involves the visual system's ability to detect drift of a foveating image  Signal an appropriate corrective eye movement to refoveate the image of regard
  5. 5. Vestibulo-ocular reflex
  6. 6. Neural integrator  A gaze- holding network : Complex integration between cortical centers, cerebellum, ascending vestibular pathways and ocular motor nuclei
  7. 7.  When the eye is turned in an extreme position in the orbit, the fascia and ligaments that suspend the eye exert an elastic force to return toward the primary position  To overcome this force, a tonic contraction of the extraocular muscles is required
  8. 8. Failure of control system- disruption of steady fixation A. Nystagmus B. Saccadic intrusion or saccadic oscillations
  9. 9. Nystagmus  Nystagmus is a repetitive, involuntary to and fro movement of the eyes (horizontal, vertical or torsional) with 2 phases: 1. Involuntary defoveating drift of the eye from the target of interest followed by 2. Corrective refixation saccade back to the target
  10. 10. Terminologies • Saccade/ Pursuit • Jerk / Pendular • Null zone • Amplitude • Frequency • Intensity • Conjugate / Dissociated
  11. 11. Saccade/ Pursuit  Saccades are sudden, simultaneous movements of both eyes in the same direction to place the object of interest on to the fovea  Pursuit eye movements allow the eyes to closely follow a moving object located by the saccadic system  Pursuit differs from the vestibulo-ocular reflex, which only occurs during movements of the head and serves to stabilize gaze on a stationary object
  12. 12. Jerk / Pendular Jerk nystagmus Pendular nystagmus Alternation of slow defoveating drift and rapid corrective saccade in opposite direction Sinusoidal oscillation with slow phase in both directions and no corrective saccade Direction of jerk nystagmus = direction of the fast phase Pendular nystagmus may be horizontal or vertical • Right or left beating nystagmus • Upbeat or downbeat nystagmus Not characterised by right,left,up,down beating as there is no fast phase
  13. 13. Pendular nystagmus Jerk nystagmus
  14. 14. Amplitude  Amplitude is the excursion of the nystagmus  Fine : less than 50  Medium : 50-150  Coarse : greater than 150
  15. 15. Frequency  Frequency is the number of to and fro movements in one second  Described an cycles/sec or Hertz (Hz)  Slow : (1-2 Hz)  Medium : (3-4 Hz)  Fast: (5 Hz or more)
  16. 16. Intensity  Intensity = amplitude x frequency  Null zone: position where intensity of nystagmus is minimized, foveation period long  Patient assumes a head posture, such that the eyes are in null zone
  17. 17. Conjugate/Dissociated  Conjugate : Nystagmus which is symmetric in direction, amplitude and rate between two eyes  Dissociated: When it differs in any one of the parameters between two eyes  Disconjugate: Direction of the oscillations differ between two eyes
  18. 18. Schematic for Nystagmus
  19. 19. Nystagmus waveforms
  20. 20. Alexanders law  It states that the amplitude of jerk nystagmus is largest in the gaze of direction of fast component  Grade I : nystagmus only in the direction of the fast component  Grade II : nystagmus in primary gaze position  Grade III : nystagmus evident in all positions of the eyes
  21. 21. Classification • Optokinetic • Vestibular • End-point Physiological • Congenital nystagmus • latent nystagmus • Spasmus nutans Early onset (childhood) • Gaze-evoked • Vestibular • Upbeat/downbeat • Dissociated nystagmus • Periodic alternating nystagmus Pathological
  22. 22. Physiological  End point nystagmus  Vestibular (caloric or rotational) nystagmus  Optokinetic nystagmus
  23. 23. End point nystagmus  Jerk nystagmus  On looking extreme lateral or upwards  Small amplitude <20 and Angle of gaze > 450 , dampens in 6 secs  Common in older patients  Pathological if-  Asymmetric  Persistent nystagmus  Other features physiological
  24. 24. Vestibular nystagmus  Jerk nystagmus due to altered inputs from vestibular nuclei to PPRF physiological
  25. 25. Vestibular nystagmus Types:  Rotatory vestibular nystagmus- stimulation of vestibular labyrinth or nerve secondary to rotation  Caloric vestibular nystagmus: • Cold water : opposite side • Warm water : same side • Cold water in both ears: upwards • Warm water in both ears : downwards
  26. 26. physiological Optokinetic nystagmus  Jerk nystagmus  Induced by moving a full visual field stimulus  Slow phase (pursuit) : eye follows the target  Fast phase ( saccade): eye fixates on next target  Uses: Detecting malingering Testing visual potential in children
  27. 27. Early onset (childhood)  Congenital nystagmus  Latent nystagmus  Spasmus nutans
  28. 28. Congenital nystagmus (Infantile nystagmus syndrome)  80% of all nystagmus  Usually not noted at birth , apparent during first few months of life  Positive family history may be present
  29. 29. Characteristics Congenital nystagmus  Horizontal nystagmus ( mixed pendular and jerk)  Bilateral conjugate movements of the eyes  With or without normal visual acuity  Head turn to achieve null point  Accentuation with distant fixation and decreased by convergence  Abolished in sleep  No oscillopsia  Strabismus present in 15% patients
  30. 30.  Reverse response to OKN stimulus ( fast phase in direction of moving OKN drum)  Exponential increase in velocity of slow phase with distance from fixation Congenital nystagmus
  31. 31. Treatment  Base out prisms to induce convergence (dampens the nystagmus and may improve visual acuity)  Use of prisms to shift the viewing position to null position Congenital nystagmus
  32. 32. Surgical Congenital nystagmus  Includes moving the extraocular muscles to place the null zone in primary position(kestenbaum procedure)  Recessing all 4 rectus muscles to decrease tension (large recession procedure)
  33. 33. Latent nystagmus (Fusional maldevelopment nystagmus syndrome)  Conjugate jerk nystagmus  Beginning or accentuation when binocular fusion is disrupted  After mono-ocular occlusion- fast phase beats towards viewing eye; slow phase towards the other  Congenital esotopia  May co-exist wit INS  Manifest latent nystagmus- latent nystagmus present with both eyes open during physiological suppression
  34. 34. Spasmus nutans Triad of symptoms:  Pendular Nystagmus  Head nodding  Torticollis (head tilt or head turn)
  35. 35. Spasmus nutans  Onset usually in the first year of life (3-15 months)  Disappears by 3-4 yrs of age  Intermittent , binocular, small-amplitude, high frequency, horizontal pendular nystagmus oscillations  It can be monocular, asymmetric, and variable in different positions of gaze  Usually benign  Neuroimaging recommended ( gliomas may mimic spasmus nutans)
  36. 36. Infantile monocular pendular nystagmus  Monocular vertical or elliptical high frequency nystagmus  Heimann-Bielchowsky phenomenon- with long standing poor vision  Usually due to visual loss(optic neuropathy, amblyopia or chiasmal glioma)
  37. 37. Acquired nystagmus Nystagmus associated with poor vision (sensory)  Anterior segment: cataract, aniridia  Retinal diseases: RB, ROP, Intrauterine infections Nystagmus associated with neurological diseases (motor)  End gaze paretic nystagmus  Vestibular nystagmus  Downbeat nystagmus  Upbeat nystagmus  Periodic alternating nystagmus  Dissociated nystagmus
  38. 38. Gaze paretic nystagmus  Most common type  Jerk nystagmus at 30° of fixation  Fast phase in direction of eccentric target  Absent in primary position and is not visually disabling
  39. 39. Gaze paretic nystagmus  Dysfunction of neural integrator- nucleus prepositus hypoglossi and medial vestibular nucleus  Symmetric- mental fatigue: barbiturates, anticonvulsants, tranquilizers  Asymmetric- lesions of brain stem, cerebellum and cerebrum
  40. 40. Gaze paretic nystagmus
  41. 41. Vestibular nystagmus Feature Peripheral Central Disease of vestibular origin Rotary nystagmus Disease of the brainstem Pure horizontal, vertical Direction • Decreased innervation-slow component towards affected ear • Increased innervation-fast component toward affected ear • Direction of nystagmus may change with gaze • Lesion contralateral to fast component Visual fixation Inhibits nystagmus No inhibition Severity of vertigo Severe Mild Induced by head Often Rare movements Associated eye movement deficits None Pursuit or saccadic defects Other findings Hearing loss, tinnitus CNS involvement
  42. 42. Upbeat nystagmus  Type of jerk nystagmus with fast phase upward in primary position  Often worsens in upgaze  Causes: lesions of lower pontine tegmentum, medulla, cerebellar vermis, midbrain • Multiple sclerosis, infarction, intra-axial tumor, brainstem encephalitis, cerebellar degeneration  Rx: base up prisms in reading glasses can be used to force the eyes downward
  43. 43. Upbeat nystagmus
  44. 44. Downbeat nystagmus  Type of jerk nystagmus with fast phase downward in primary position  Often worsens in downgaze(convergence)  Oscillopsia is usually prominent  Causes:  lesions at cerebellum and pons- infarction, cerebellar degenerations, tumors, multiple sclerosis, congenital malformations  Vitamin B12 deficiency, magnesium deficiency, lithium toxicity, Wernicke’s encephalopathy  Rx: Base down prisms in reading glasses can be used to force the eyes upward
  45. 45. Downbeat nystagmus
  46. 46. Periodic alternating nystagmus (PAN)  A repetitive cycling of right beating and left beating nystagmus in primary gaze  PAN is a conjugate, horizontal jerk nystagmus with the fast phase beating in one direction for a period of 1-2 minutes  An intervening null phase lasting 10-20 seconds  Nystagmus begins to beat in the opposite direction for 1-2 minutes then, the process repeats itself
  47. 47. Periodic alternating nystagmus  Periodic alternating head turn towards fast component to minimise nystagmus & oscillopsia  Causes:  lesions of the cerebellum  Severe binocular vision loss- vitreous hemorrhage, cataract, chronic papilloedema
  48. 48. Periodic alternating nystagmus
  49. 49. Dissociated Nystagmus Difference between two eyes in amplitude of ocular oscillations A. Acqiured pendular nystagmus in adults: • Lesions of pons, medulla, midbrain, cerebellum • Oculopalatal myoclonus- associated tremors of soft palate tongue, facial muscle, pharynx
  50. 50. Dissociated Nystagmus B. Monocular or bilateral vision loss 1. Monocular - • Children: High frequency pendular nystagmus • Adults: low frequency, irregular, vertical dift and jerk nystagmus • Abolished with recovery of vision 2. Binocular: • large amplitude oscillations superimposed with small amplitude ones • Impaired vestibulo-ocular response • Head nodding present
  51. 51. Dissociated Nystagmus C. Seesaw nystagmus:  Disconjugate vertical pendular nystagmus  Elevation and intorsion of one eye simultaneous with depression and extorsion of other eye  Followed by reversal of cycle, so that the eyes move like a seesaw
  52. 52. Seesaw nystagmus  Causes:  Parasellar lesions, pituitary tumors  Less common- head trauma, brain stem infarction  Produces very disabling oscillopsia that responds poorly to any Rx
  53. 53. Dissociated Nystagmus D. Inter nuclear ophthalmoplegia  Lesion of medial longitudinal fibers  Isolated slowing of adduction of ipsilateral eye  Abducting nystagmus of other eye in horizontal gaze opposite to lesion
  54. 54. Convergence-retraction nystagmus  Not truly a nystagmus  b/l adducting saccades causing convergence of both eyes  Elicited by having the patient to look up, the eyes converge & retract  Co-contraction of all extra-ocular muscle  Causes: Dorsal midbrain lesions  Collier’s sign- paresis of upgaze, pupillary light near dissociation, skew deviation, bilateral eyelid retraction
  55. 55. Convergence-retraction nystagmus
  56. 56. Nystagmus associated with strabismus  Manifest-latent nystagmus  Manifest nystagmus  Nystagmus blockage syndrome
  57. 57. Manifest nystagmus Manifest-latent nystagmus Pendular nystagmus Jerk nystagmus No change on abduction Increased on abduction No change on covering one Increase on covering one eye eye Null zone is present Fast phase always towards fixing eye Less commonly associated with infantile esotropia Always associated with esotropia Binocular visual acuity same as uniocular Binocular visual acuity better than uniocular
  58. 58. Nystagmus blockage syndrome  Inverse relationship with esotropia  Esotropia is a mechanism of blocking the nystagmus  The fixing eye is preferred to be in adduction ,face turn is in the direction of fixing eye
  59. 59. Nystagmoid conditions • Reflex saccades to objects in visual field is inhibited by pathways from frontal lobe to basal ganglia and superior colliculus • Frontal lobe disease- inappropriate saccades • Alzhimer’s disease, Huntington disease, progressive supranuclear palsy, schizophrenia  Saccadic intrusions: 1. Normal intersaccadic intervals 2. Without normal intersaccadic intervals
  60. 60. Saccadic intrusion with normal inter-saccadic interval Square wave kerks Macro- square wave kerks Macrosaccadic oscillation
  61. 61. Saccadic intrusion without normal inter-saccadic interval  Ocular flutter- Burst of small amplitude, high frequency, horizontal movements  Opsoclonus (saccadomania) – multidirectional eye movements, high frequency, high amplitude
  62. 62. Saccadic intrusion without normal inter-saccadic interval Ocular flutter/Opsoconus Etiology – • Unknown in healthy individuals • Omnipause neurons of pons • Neuroblastoma • Small cell carcinoma of lung • Cancer of breast and ovaries • Multiple sclerosis, brainstem encephalitis
  63. 63. Ocular bobbing  Characterized by rapid downward movement of both eyes  Followed by slow drift back to midline  Causes: • Comatose patients with massive pontine lesion • Metabolic encephalopathy
  64. 64. Superior oblique myokymia  Defined as high frequency oblique oscillation of one eye due to intermittent firing of the superior oblique muscle  Produces oscillopsia or intermittent vertical diplopia  Very small amplitude observed in slit lamp
  65. 65. Superior oblique myokymia  Usually benign  No underlying etiology is found  Neuroimaging : r/o post fossa tumors  Refractory cases: • Carbamazepine • Surgical weakning of the superior oblique muscle can be performed
  66. 66. Treatment Nonsurgical : non neurological causes  Optical devices • Glasses: High minus lenses stimulate accommodative convergence and thus dampens nystagmus • Contact lenses: helpful in high refractive errors by giving good visual stimulus for fusional control
  67. 67. Nonsurgical : non neurological causes  Prisms : 1. To induce fusional convergence by using 7 PD base out prism in front of each eye 2. Pre op evaluation in a patient with face turn - prisms are inserted with the apex in direction of gaze Useful as a diagnostic trial ,but as a therapeutic alternative are not helpful
  68. 68. Nonsurgical : non neurological causes Occlusion therapy:  Trials with conventional occlusion have been found to be effective  As amblyopia gets corrected and vision improves, nystagmus finally decreases
  69. 69. Pharmacologic management  The drugs hypothetically inhibit excitatory neurotransmitters within CNS 1. Baclofen (GABAB receptor agonist) : congenital nystagmus, seesaw nystagmus, periodic alternating nystagmus 2. Carbamazepine: widely used for superior oblique myokymia
  70. 70. Pharmacologic denervation  Botulinum toxin A act by blocking the neuromuscular transmission • 3 units of toxin is injected in each of the 4 horizontal rectus muscles • Single large dose of drug into the retrobulbar space • Effect last for only few months
  71. 71. Surgical Based on 2 principles:  To shift the null position if any to the primary position  To reduce the amplitude of the nystagmus by weakening the muscle force of all recti
  72. 72. Kestenbaum surgery  Devised first surgical approach using recession-resection of all four horizontal recti  Advocated an equal amount of 5 mm for all recti  Left face turn (null in dextroversion):  Right eye: LR recession & MR resection  Left eye : MR recession & LR resection
  73. 73. Anderson surgery  Advocated only recessions  Left face turn (null in dextroversion):  Right eye : LR recession  Left eye : MR recession
  74. 74. Parks surgery  Recommended lesser amount of recessions and resections for medial rectus surgery compared to lateral rectus surgery  Advocated a 5,6,7,8 plan  MR recession : 5 mm  MR resection : 6 mm  LR recession : 7 mm  LR resection : 8 mm
  75. 75. Summary  Nystagmus- Slow defoveating drift followed by rapid corrective saccade eye movement  Physiological, childhood onset, pathological  Abnormalities of cortical, subcortical and ocular motor nuclei with vesibular nuclei and cerebellum  Inability to maintain fixation, decreased fixation and oscillopsia  Saccadic intrusions- not ture nystagmus with lack of slow component, rapid defoveating drift with fixation intervals  Medical, optical, surgical management may be satisfactory in achieving null point
  76. 76. Bibliography  American Academy of Ophthalmology. Neuro- Ophthalmology. Section 5. 2013-2014  Kanski Jack J. Clinical Ophthalmology: A Systematic Approach. 7th ed. Elsevier;2013: 841- 846.  Myron Yanoff & Jay Duker. Ophthalmology,3rd edition,2008: 9:1040-1048.  Khurana AK. Anatomy and physiology. 2nd ed. New Delhi; rerinted 2010
  77. 77. Thank you

×