Neural Mechanisms Engaged in Control of Eye Movements

This study is currently recruiting participants. (see Contacts and Locations)
Verified June 2014 by Meir Medical Center
Sponsor:
Information provided by (Responsible Party):
Meir Medical Center
ClinicalTrials.gov Identifier:
NCT00999934
First received: October 21, 2009
Last updated: June 23, 2014
Last verified: June 2014
  Purpose

The purpose of eye movements is to ensure clear, optimal vision. In order to see clearly, images must be held steady on the retina. Best visual acuity is achieved when the image of the object of interest is brought to and held on the fovea of the retina. Two main types of eye movements are responsible for that: those that keep images stable on the retina (gaze holding mechanisms) and those that change the line of sight (gaze shifting mechanisms). Several functional classes of eye movements have been defined; each has distinctive physiological properties that suit best to its particular task. Thus, vestibular and optokinetic eye movements hold images of the seen world steady on the retina during perturbations of the head. Saccades are rapid eye movements that bring the image of an object of interest, detected in the periphery of vision, onto the fovea where it can be seen best. Smooth pursuit eye movements place the images of a moving target close to fovea. Vergence eye movements place the images of a single object simultaneously onto both foveae.

Each functional class of eye movements relies on a different neural substrate. The clinical significance of it is that impairment of a specific class of eye movement points to involvement of distinct structures or pathways within the brain. Thus, abnormalities of ocular motility are often the clue to the anatomical localization of neurological disorders.

Significance: This study will contribute to understand how the brain governs production of eye movements, and provide better insight on interaction between sensory (visual) and motor (eye movement) system, i.e. sensory-motor interaction. It will also contribute to identify pathophysiological mechanisms underlying human diseases and will improve the investigators' ability to diagnose and encourage development of new therapeutic strategies.

Methods: The investigators will measure eye and head movements using the magnetic scleral search coil technique. The magnetic search coil technique is the most sensitive and accurate technique used in modern ocular motor and vestibular research for measuring horizontal, vertical and torsional eye movements. The coils are easy to apply and well tolerated over a wearing period of up to 45 minutes per recording session.

Population: A grand total of about 250 individuals (normal subjects and patients) will be recruited for the study. Patients will be recruited from the in- and out-patients of the Neurology and Neuro-ophthalmology services of Meir Medical Center. Healthy normal subjects will be recruited from faculty and staff of Meir Medical Center.

Criteria for inclusion/exclusion: The investigators will study patients with neurological disorders causing abnormal eye movements: Degenerative CNS diseases, extrapyramidal disorders, Spino-cerebellar ataxias, Cerebrovascular diseases, demyelinating diseases, Ocular motor and vestibular palsies, Mitochondrial and other ocular myopathies. Only patients who are medically stable and are able to give informed consent will be included in the study. Criteria for excluding subjects will include eye disease such as corneal or scleral abrasion or disease, glaucoma, refractive errors greater than 2 diopters and concurrent medication with CNS-active agents.


Condition
Degenerative Diseases of the Central Nervous System
Ocular-motor and Vestibular Diseases

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective

Further study details as provided by Meir Medical Center:

Primary Outcome Measures:
  • Quantitative measure of eye movement and vestibulo-ocular abnormalities [ Time Frame: December 1, 2012 ] [ Designated as safety issue: No ]

Estimated Enrollment: 250
Study Start Date: July 2009
Estimated Study Completion Date: February 2016
Estimated Primary Completion Date: June 2015 (Final data collection date for primary outcome measure)
  Eligibility

Ages Eligible for Study:   18 Years to 85 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Population: A grand total of about 250 individuals (normal subjects and patients) will be recruited for the study. Patients will be recruited from the in- and out-patients of the Neurology and Neuro-ophthalmology services of Meir Medical Center. Healthy normal subjects will be recruited from faculty and staff of Meir Medical Center.

Criteria

Inclusion Criteria:

  • Patients with degenerative CNS diseases, extrapyramidal disorders, Spino-cerebellar ataxias, Cerebrovascular diseases, demyelinating diseases, Ocular motor and vestibular palsies, Mitochondrial and other ocular myopathies.
  • Patients who are medically stable and are able to give informed consent will be included in the study.

Exclusion Criteria:

  • Subjects with eye disease such as corneal or scleral abrasion or disease, glaucoma, refractive errors greater than 2 diopters.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00999934

Locations
Israel
Department of Neurology Recruiting
Kfar Saba, Israel, 44281
Contact: Carlos R Gordon, MD, DSC    972-9-7471581    cgordon@post.tau.ac.il   
Principal Investigator: Carlos R Gordon, MD, DSc         
Sponsors and Collaborators
Meir Medical Center
Investigators
Principal Investigator: Carlos R Gordon, M.D.; D.Sc. Department of Neurology, Meir Medical Center, Kfar Saba and Sackler Faculty of Medicine, Tel Aviv, Israel.
  More Information

No publications provided

Responsible Party: Meir Medical Center
ClinicalTrials.gov Identifier: NCT00999934     History of Changes
Other Study ID Numbers: eyemovements01
Study First Received: October 21, 2009
Last Updated: June 23, 2014
Health Authority: Israel: Ethics Commission
Israel: Israeli Health Ministry Pharmaceutical Administration

Additional relevant MeSH terms:
Vestibular Diseases
Neurodegenerative Diseases
Labyrinth Diseases
Ear Diseases
Otorhinolaryngologic Diseases
Nervous System Diseases

ClinicalTrials.gov processed this record on July 20, 2014