Dynamic visual tests to identify and quantify visual damage and repair following demyelination in optic neuritis patients

• Published in: Journal of visualized experiments 2014-04 (86)
• Main Authors: Raz, Noa, Hallak, Michal, Ben-Hur, Tamir, Levin, Netta
• Format: Article
• Language: English
• Subjects: Demyelinating Diseases - diagnosis; Demyelinating Diseases - physiopathology; Humans; Medicine; Optic Neuritis - diagnosis; Optic Neuritis - physiopathology; Vision Tests - methods; Vision, Binocular - physiology; Vision, Monocular - physiology
• ISSN: 1940-087X; 1940-087X
• DOI: 10.3791/51107

In order to follow optic neuritis patients and evaluate the effectiveness of their treatment, a handy, accurate and quantifiable tool is required to assess changes in myelination at the central nervous system (CNS). However, standard measurements, including routine visual tests and MRI scans, are not sensitive enough for this purpose. We present two visual tests addressing dynamic monocular and binocular functions which may closely associate with the extent of myelination along visual pathways. These include Object From Motion (OFM) extraction and Time-constrained stereo protocols. In the OFM test, an array of dots compose an object, by moving the dots within the image rightward while moving the dots outside the image leftward or vice versa. The dot pattern generates a camouflaged object that cannot be detected when the dots are stationary or moving as a whole. Importantly, object recognition is critically dependent on motion perception. In the Time-constrained Stereo protocol, spatially disparate images are presented for a limited length of time, challenging binocular 3-dimensional integration in time. Both tests are appropriate for clinical usage and provide a simple, yet powerful, way to identify and quantify processes of demyelination and remyelination along visual pathways. These protocols may be efficient to diagnose and follow optic neuritis and multiple sclerosis patients. In the diagnostic process, these protocols may reveal visual deficits that cannot be identified via current standard visual measurements. Moreover, these protocols sensitively identify the basis of the currently unexplained continued visual complaints of patients following recovery of visual acuity. In the longitudinal follow up course, the protocols can be used as a sensitive marker of demyelinating and remyelinating processes along time. These protocols may therefore be used to evaluate the efficacy of current and evolving therapeutic strategies, targeting myelination of the CNS.