Transcript Understanding and Treatment of Infantile Nystagmus Syndrome
Understanding and Treatment of Infantile Nystagmus Syndrome
Richard W. Hertle, MD, FAAO, FACS, FAAP Chief of Pediatric Ophthalmology, Children’s Hospital of Pittsburgh Director of Ocular Motility, The UPMC Eye Center Professor of Ophthalmology, The University of Pittsburgh The Laboratory of Visual and Ocular Motor Neurophysiology
Examination Techniques: Highlights
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Acuity
Binocular and Monocular
Gaze-Dependent
Color, Contrast Ocular Motor
Strabismus
Nystagmus – “nulls”
Head Posture
Accommodation Refraction
Objective
Visual Acuity Testing
20/400 20/200 20/100 20/50 20/25
Evaluation Techniques: Afferent System
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Vision testing procedures
Behavioral Vision Testing (acuity, color, stereo) Visual Evoked Responses (flash, pattern, sweep) Electroretinography (flash, pattern) Contrast, Color and Visual Field Testing
Evaluation: Efferent System Eye Movement Recordings
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Methods
High speed photographic methods.
“Contact” electrooculography.
Infrared reflectance oculography.
Scleral contact lens/magnetic search coils.
Eye Movement Recordings
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Diagnosis/Differentiation of Eye Movement Disorders.
Utility as an “Outcome Measure” in Clinical Research.
Deg R L
10
Deg
0 5 -5 0 1 Foveation Periods Within ±..5° by ±4°/sec Window 2 Time (sec) 3 4 5
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Eye Movement Recordings
Age Distribution Value of data
Diagnosis.
Classification.
Etiology.
Therapy.
Research.
30% 25% 20% 15% 10% 5% 0% <2
685 Patients 1998-2005
<5 <10 <15
Age (year)
<20 <30 >31
Afferent System Conception Development Birth Infancy Efferent System
Vision Vergence, Versions STABLE OCULAR MOTOR SYSTEM
CEMAS
Disease Name Criteria INFANTILE NYSTAGMUS SYNDROME (INS) [Old Congenital Nystagmus and “Motor and Sensory” Nystagmus]
Infantile onset, ocular motor recordings show diagnostic (accelerating) slow phases
Common Associated Findings General Comments
Conjugate, horizontal-torsional, increases with fixation attempt, progression from pendular to jerk, family history often positive, constant, conjugate, with or without associated sensory system deficits (e.g., albinism, achromatopsia), associated strabismus or refractive error, decreases with convergence, null and neutral zones present, associated head posture or head shaking, may exhibit a ”latent” component, “reversal” with OKN stimulus or (a)periodicity to the oscillation. Candidates on Chromosome X and 6 May decrease with induced convergence, increased fusion, extraocular muscle surgery, contact lenses and sedation.
Waveforms may change in early infancy, head posture usually evident by 4 years of age. Vision prognosis dependent on integrity of sensory system.
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Nystagmus and Vision
“Sensory” System
Refractive Error Amblyopia Abnormal Binocular Vision Ocular Media Damage Retinal Disease Nycloptia/Photophobia Optic Nerve Disease Visual Cortex Disease
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“Motor” System
Oscillation Strabismus Abnormal Pursuit (tracking) Abnormal Saccades (fast eye movements)
“MOTOR” SYSTEM TREATMENT
Medications
Visual Training (strabismus, binocular dysfunction)
Acupuncture
Biofeedback
Vibratory Stimulation
Prisms, Telescopes, Contact Lenses
Botox
Eye Muscle Surgery
Medical Treatments
Spectacles
Contact Lenses
Low Vision Aids
Penalization (patching, drops)
Medical Treatments
Photophobia Nystagmus
• Sedatives, Hypnotics, Neuroleptics, Anti-seizure drugs • Acupuncture, Biofeedback, Vibratory Stimulation
Strabismus and binocular dysfunction
• Orthoptics • Spectacles • Penalization
“Nystagmus” Surgery
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Effect a Positive Change on the Oscillation
Improve Waveform
Increase Foveation
Broaden Null Position
Improve Periodicity Treat Anomalous Head Positions
ANIMAL MODEL OF INS
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Achiasmatic Belgian Sheepdogs Ocular Motor Behavior Ocular Motor Analysis Infrared Oculography Recording Preoperative and Postoperative
Visual Behavior Eye Movement Recordings
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HUMAN CLINICAL TRIALS EYE MUSCLE SURGERY AND INS Simple tenotomy of all 4 horizontal recti Reattachment at the original insertion Final Effect related to underlying visual system disease Hertle RW
, Dell’Osso LF, FitzGibbon, EJ, Yang D, Mellow SD. Horizontal Rectus Muscle Tenotomy In Children with Infantile Nystagmus Syndrome: A Pilot Study.
Journal of AAPOS 2004:8;539-548
Hertle RW
, Dell’Osso LF, FitzGibbon, EJ, Thompson DJS, Yang D, Mellow S. Horizontal Rectus Tenotomy In Patients with Congenital Nystagmus: Results In Ten Adults Ophthalmology 2003:11;2097-2115
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HUMAN CLINICAL TRIALS EYE MUSCLE SURGERY AND INS Increased Foveation (amount of time during a beat of INS during which the eye is moving at <4 deg/sec and within a few degrees of the target – when the eye/brain “sees”) t Targe Preferred OD Fixing Under Binocular Conditions t Targe
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HUMAN CLINICAL TRIALS EYE MUSCLE SURGERY AND INS Improved Waveforms (Pure Jerk and Pendular to Jerk/Pendular with foveation) Target Preferred OD Fixing Under Binocular Conditions Target
HUMAN CLINICAL TRIALS EYE MUSCLE SURGERY AND INS
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Increased Breadth of The Null Zone 10 degrees 5 sec R L 10 degrees 5 sec Pre-Operative R L Post-Operative
HUMAN CLINICAL TRIALS EYE MUSCLE SURGERY AND INS
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1-3 Lines of Recognition Acuity Increase Pre-Post Tenotomy Acuity 1 0.9
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0.6
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0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Patient #
LogMar OU Pre LogMar OU Post
HUMAN CLINICAL TRIALS EYE MUSCLE SURGERY AND INS
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Improved Visual Recognition Time (Speed of Recognition) 10 00 Lo gM A R 0.94 (20/176, S ize 7) 8 00 6 00 4 00 -40 -30 -2 0 -1 0 0 1 0 20 V e lo city (d e gre e s/s ec ) 3 0 4 0
GAZE DEPENDENT VISUAL ACUITY 30 deg 20 deg 10 deg E F P 0 deg 10 deg 20 deg 30 deg
Fig. 1.Gaze angle
HUMAN CLINICAL TRIALS EYE MUSCLE SURGERY AND INS
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Improved Gaze Dependent Visual Acuity (GDVA) PRE-POST GDVA PT. 19
1 0.9
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0 -30 -20 -10 0 10
DEGREES OF GAZE
20 30 PREOP POSTOP
PRE-POST GDVA PT. 25
1 0.9
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0 -30 -20 -10 0 10
DEGREES OF GAZE
20 30 PREOP POSTOP
Enthesial Area Annulus Of Zinn “Myotendon”
Myelin Axon 2u CONTROL HUMAN ENTHESIS Nerve Ending Capillary 500u 2u
TREATMENT:ANIMAL MODEL
Etiologic
INS with Gene Defect (RPE65 – Leber’s in Humans)
Genetic Therapy*
Conclusions Ask For:
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Accurate Evaluation
Afferent System Efferent System Accurate Diagnosis
Sensory System Deficits Nystagmus Type Strabismus Head Posturing Medical Treatment Options Surgical Treatment Options Treatment versus “CURE”