This work was supported by the Caesarea Edmond &#38; Benjamin de Rothschild Foundations.

The protocol follows the Hadassah Hebrew University Ethics Committee guidelines for studies in human subjects. To avoid the effect of myopia or refractive errors on test results, the protocols should be performed while patients wear their eyeglasses (corrected vision).
Object From Motion (OFM) protocol:
1. Test Initiation and Instructing Subjects
<ol>
	<li>Seat the subject 50 cm in front of the computer screen.</li>
	<li>Open the OFM software.</li>
	<li>Instruct the subject that he will be presented with motion defined objects. Instruct him to respond as correct and as fast as possible by pressing the "A" keyboard and then verbally naming the perceived object.</li>
	<li>Following response, a screen indicating "press the space bar" will appear. Instruct the subject to press the space bar when ready to identify the next stimulus.</li>
	<li>Explain to the subject that stimuli may appear at very hard to-perceive velocities or at some easier to perceive ones.</li>
</ol>
2. Learning Phase
Enter "learning OFM" at the command line. Subject will now be presented with 4 example stimuli. This phase is conducted when subject&#39;s both eyes are open.
3. Testing Phase
In general, each OFM test includes 20 stimuli. All are first presented at the lowest velocity of 4 pixels/sec. Those not recognized will be then presented at the next velocity of 5.5 pixels/sec. Those not recognized, will be then presented at the next velocity of 7.5 pixels/sec and so on, going through 10 pixels/sec, 13.5 pixels/sec, 18 pixels/sec, and till the fastest velocity of 24.5 pixels/sec. Velocities were defined based on the exponent y=3*e0.3. If five consecutive stimuli in a certain velocity were not recognized, the next stimuli will be presented at the next faster velocity to avoid frustration in the patients. This will result in shortening test length which generally is longer as recognition is worse (necessitating the passage through larger number of velocities per stimulus).
<ol>
	<li>Cover subject&#39;s one eye with an eye patch. Every eye patch may be adequate as long as it supplies full coverage.</li>
	<li>Enter "OFM objects" at the command line.</li>
	<li>Choose one stimuli set (software includes 4 stimuli sets. Each set includes 20 different objects. Selection may be random. However, make sure that you apply different stimuli sets for each of the tested eyes; Apply different stimuli sets for subsequent learning time points in case of longitudinal assessment).</li>
	<li>A prompt asking you to enter subject&#39;s name, tested eye and testing date will appear. Complete required information.</li>
	<li>Carefully monitor the subject and respond to the subject while she/he completes the task as follows:
	<ol>
		<li>When a stimulus appears the subject must press the "A" button on the keyboard and name the identity of the presented stimulus.</li>
		<li>Press the left mouse button for a correct answer or the right mouse button for a wrong answer.</li>
		<li>Subject presses the "space bar" on the keyboard for initiation of the next stimulus.</li>
		<li>This procedure (steps 3.5.1-3.1.5.3) continues until all 20 stimuli in the set are either recognized or presented at the fastest velocity.</li>
	</ol>
	</li>
	<li>Repeat the whole procedure (from step 3.1) for the subject&#39;s second eye using a different set of stimuli.</li>
</ol>
Time-constrained Stereo Protocol:
1. Test Initiation and Instructing Subjects
<ol>
	<li>Seat the subject 50 cm in front of the computer screen.</li>
	<li>Open the Stereo software.</li>
	<li>Instruct the subject that he will be presented with 3 dimensional (3D) shapes and will have to name the perceived shape as correct and fast as possible. Shapes will be one of the following: a circle, a square, a triangle, or a star.</li>
	<li>Explain to the subject that stimuli may appear at very hard to perceive conditions or at some easier to perceive ones.</li>
	<li>Instruct the subject to wear the 3D glasses.</li>
	<li>Turn off the room lightening.</li>
</ol>
2. Learning Phase
Enter "learning Stereo" at the command line. Subject will be now presented with 4 repetitions of each shape, presented at the longest stimuli duration (500 msec) and at the easiest disparity (840 sec of arc) conditions. Following the 3D presentation condition, a 2D presentation will follow for each shape. In the latter, a line marking shapes contours will be added, to make sure subject perceived the dimensions of the presented shape. Subjects, who did not succeed at this easy condition, will not be tested at the next phase.
3. Testing Phase: Stereopsis Perception as a Function of Binocular Disparity
The 4 shapes will be presented for 500 msec at 4 different disparity conditions: 120, 300, 540, and 840 sec of arc.
<ol>
	<li>Enter "Stereo Disparity" at the command line.</li>
	<li>A prompt asking you to enter subject&#39;s name and testing date will appear. Complete required information.</li>
	<li>Stimulus appears</li>
	<li>Subject names the presented shape. Responses are coded by the examiner at key buttons 1-4 (i.e. press the 1, 2, 3, or 4 key buttons for subject&#39;s verbal responses of "a circle", "a square", "a triangle", or "a star", respectively). Due to lighting conditions and the fact that the subject wears 3D glasses, he cannot code the responses by himself).</li>
	<li>Subject presses any key to continue to the next stimulus. The order of stimuli presentation is random.</li>
</ol>
4. Testing Phase
Stereopsis perception as a function of stimulus presentation time. The 4 shapes will be presented for disparities of 540 and 840 sec of arc at either 40, 60, or 100 msec durations.
<ol>
	<li>Enter "Stereo Duration" at the command line.</li>
	<li>Repeat steps 3.2-3.5.</li>
</ol>

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The authors declare no competing financial interests.

Optic neuritis is a demyelinative disease of the optic nerve, causing acute visual loss. Though considered transient when using standard visual testing1, patients continue to perceive difficulties in performing everyday visual tasks. We argue that dynamic visual tests are adequate to identify and quantify these sustained deficits. This is since dynamic but not static visual functions depend on projection rates, and may be more vulnerable to delayed projection following demyelination.
T...

Optic neuritis as a model for tracking tissue degeneration and repair
Multiple sclerosis (MS) is a chronic inflammatory neurodegenerative disease of the central nervous system (CNS) and is the leading cause of nontraumatic neurological disability in young adults in developed countries. Demyelination is considered the most characteristic histopathological feature of MS. Recent studies, however, revealed that MS is also a neurodegenerative disease with early neuroaxonal damage1-3.
Optic neuritis (ON), inflammation of the optic nerve, is the presenting symptom in 20% of MS patients and at least 50% of those suffering from MS experience at least one episode of ON during their lifetime4. Unlike other locations of MS lesions that do not always correlate to the clinical manifestations, demyelinating episode of the optic nerve typically results in distinctive manifestation of acute visual loss. Given its comorbidity with MS and its prominent clinical features, ON offers a unique opportunity for tracking tissue degeneration and repair and their consequences in a single MS lesion.
The need for improved methods for tracking tissue degeneration and repair in vivo
Pathologic studies in MS implicate demyelination as a principal cause of axonal transection and subsequent axonal degeneration. Remyelination may prevent demyelinated axons from degenerating; however, effective remyelination may be limited as a result of repeated attacks. Therefore, current and evolving neuroprotective and regenerative therapeutic strategies in MS are aimed to prevent new attacks and promote remyelination processes in the CNS5.
In order to follow up optic neuritis patients and evaluate the efficacy of their treatment, a fine tool to quantify changes in myelination at the CNS is required. However, the standard measurements, including routine visual tests and MRI scans, are not sensitive enough for this purpose. Routine visual tests (i.e. visual acuity, contrast sensitivity, visual fields, and color perception) may reveal cases of reduced input projection along the visual pathways but are insensitive to identify delayed projection rates, which is the role of the demyelinated fibers6,7. T2 hyperintense lesions, which are the hallmark of the disease, result from residual mixture of edema, inflammation, demyelination, axonal loss and gliosis and thus cannot differentiate between demyelination and other brain pathologies. Furthermore, standard MRI is designed to reveal qualitative tissue contrast. While these are adequate for identifying the location of unusual tissue, they are insufficient to quantitatively assess tissue properties.
Dynamic visual tests may be used as markers of demyelination and remyelination
We argue that dynamic visual functions are more appropriate than static functions to identify and quantify changes in projection latencies along the visual pathways. While accomplishment of both static and dynamic visual functions requires sufficient amount of visual input projection, only dynamic visual functions depend on projection rates. Optic nerve demyelination may thus affect dynamic rather than static visual functions, implicating the need for rapid transmission of visual input in order to perceive motion.
We have developed two behavioral tasks to assess monocular and binocular visual functions which may closely associate with projection latencies along the 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 dependent on motion perception. Using the OFM protocol, we have demonstrated a sustained deficit in the affected eyes of ON patients, evident even 12 months following the optic neuritis attack, while standard visual functions had recovered8. Furthermore, impaired performance was associated with delayed conductions (delayed P100, reflecting demyelination) and improvement in motion perception was correlated with shortening of conduction rates (reflecting remyelination; linear least squares regression with calculation of the correlation coefficient F=27.3; p=0.0005; r=-0.87)9.
The currently presented OFM protocol was updated in order to fit the test for clinical usage, including test shortening, adjusting the test software to result in an automatic output file, and to result in a motion sensitivity score.
To assess the effect of projection latencies on binocular vision, the Time-constrained Stereo protocol was developed. In this protocol, spatially disparate images are presented for a limited length of time, challenging binocular integration in time. This test was designed to test the hypothesis that due to demyelination at the affected nerve, information from the two eyes will reach the cortex at different time points impairing binocular integration in time. Testing a group of recovered ON patients (1-2.5 years following the attack), we have shown that while most patients had intact performance levels in a standard static stereo task; performance on the time-constrained stereo task was impaired in most cases10.
The OFM and the time-constrained stereo protocols provide a simple, yet powerful, way to identify and quantify processes of demyelination and remyelination along the visual pathways. These protocols may be efficient to diagnose and follow up ON and MS patients in a cost effective manner using an easy to use computer based protocol.

<table><tbody><tr><td>Personal computer, including laptops</td><td></td><td></td><td>The OFM software runs best on Mac or on Windows 7 (or higher) PC. The Stereo software runs on every personal computer.&amp;nbsp;</td></tr><tr><td>Monitor&amp;nbsp; specification</td><td></td><td></td><td>Size: at least 15inch,&amp;nbsp; Color: at least 16 bit</td></tr><tr><td>The OFM and the Stereo softwares</td><td>These are self-developed softwares</td><td></td><td>Researchers &amp;amp; physicians who are interested in these softwares may contact us at: fmri-hadassah.org</td></tr><tr><td>Red/Cyan 3D glasses (We had tested the Stereo software on the two following 3D glasses):</td><td>Nvidia &amp;amp; American Paper Optics</td><td>3D Vision Ultimate Anaglyph 3D Glasses &amp;amp; Pro X Style Red/Cyan 3D Glasses for Movies and Games on Flat Screens&amp;nbsp;&amp;nbsp;</td><td></td></tr><tr><td>Performance on our stereo task was compared to performance on the standard Randot stereo test</td><td>Stereo Optical Co.</td><td>Randot SO-002&amp;nbsp;</td><td></td></tr></tbody></table>

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

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.

OFM protocol
The protocol results in a text file, automatically summarizing subject's responses. Outcome can be analyzed in two ways:
Total score: Each stimulus presented is assigned with a stimulus weight, and the sum of weights of all identified stimuli is set as the subject's response score. The weight of a particular stimulus is set based on the speed of the stimulus, with higher weights to lower speeds. Unidentified stimuli are assigned with a zero weight. General...

Watch this Scientific Journal Video about Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients at JoVE.com

Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients

Object From Motion (OFM) and Time-constrained stereo protocols are sensitive tools to identify monocular and binocular dynamic visual function deficits, which are uniquely affected in optic neuritis patients. Furthermore, these tests may be used as quantitative noninvasive tools to assess the extent of myelination along visual pathways.

In order to follow optic neuritis patients and evaluate the effectiveness of their treatment, a handy, accurate and quantifiable tool is required to ...

dynamic-visual-tests-to-identify-quantify-visual-damage-repair

Research

JoVE Journal

Medicine

14.0K Views.  Hadassah Hebrew-University Medical Center. Object From Motion (OFM) and Time-constrained stereo protocols are sensitive tools to identify monocular and binocular dynamic visual function deficits, which are uniquely affected in optic neuritis patients. Furthermore, these tests may be used as quantitative noninvasive tools to assess the extent of myelination along visual pathways.

Video: Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients

Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats

The optomotor response and the Y-maze are behavioral tests useful for assessing visual and cognitive function, respectively. The optomotor response is a valuable tool to track changes in spatial frequency (SF) and contrast sensitivity (CS) thresholds over time in a number of retinal disease models, including diabetic retinopathy. Similarly, the Y-maze can be used to monitor spatial cognition (as measured by spontaneous alternation) and exploratory behavior (as measured by a number of entries) in a number of disease models that affect the central nervous system. Advantages of the optomotor response and the Y-maze include sensitivity, speed of testing, the use of innate responses (training is not needed), and the ability to be performed on awake (non-anesthetized) animals. Here, protocols are described for both the optomotor response and the Y-maze and examples of their use shown in models of Type I and Type II diabetes. Methods include preparation of rodents and equipment, performance of the optomotor response and the Y-maze, and post-test data analysis.

Neural degeneration in both eyes and brain as a result of diabetes can be observed through behavioral tests carried out on rodents. The Y-maze, a measure of spatial cognition, and the optomotor response, a measure of visual function, both provide insight into potential diagnoses and treatments.

The optomotor response and the Y-maze are behavioral tests useful for assessing visual and cognitive function, respectively. The optomotor response is a ...

Behavior

In vivo Imaging of Optic Nerve Fiber Integrity by Contrast-Enhanced MRI in Mice

The rodent visual system encompasses retinal ganglion cells and their axons that form the optic nerve to enter thalamic and midbrain centers, and postsynaptic projections to the visual cortex. Based on its distinct anatomical structure and convenient accessibility, it has become the favored structure for studies on neuronal survival, axonal regeneration, and synaptic plasticity. Recent advancements in MR imaging have enabled the in vivo visualization of the retino-tectal part of this projection using manganese mediated contrast enhancement (MEMRI). Here, we present a MEMRI protocol for illustration of the visual projection in mice, by which resolutions of (200 &#181;m)3 can be achieved using common 3 Tesla scanners. We demonstrate how intravitreal injection of a single dosage of 15 nmol MnCl2 leads to a saturated enhancement of the intact projection within 24 hr. With exception of the retina, changes in signal intensity are independent of coincided visual stimulation or physiological aging. We further apply this technique to longitudinally monitor axonal degeneration in response to acute optic nerve injury, a paradigm by which Mn2+ transport completely arrests at the lesion site. Conversely, active Mn2+ transport is quantitatively proportionate to the viability, number, and electrical activity of axon fibers. For such an analysis, we exemplify Mn2+ transport kinetics along the visual path in a transgenic mouse model (NF-&#954;B p50KO) displaying spontaneous atrophy of sensory, including visual, projections. In these mice, MEMRI indicates reduced but not delayed Mn2+ transport as compared to wild type mice, thus revealing signs of structural and/or functional impairments by NF-&#954;B mutations.
In summary, MEMRI conveniently bridges in vivo assays and post mortem histology for the characterization of nerve fiber integrity and activity. It is highly useful for longitudinal studies on axonal degeneration and regeneration, and investigations of mutant mice for genuine or inducible phenotypes.

In vivo Imaging of Optic Nerve Fiber Integrity by Contrast-Enhanced MRI in Mice

This video illustrates a method, using a clinical 3 T scanner, for contrast-enhanced MR imaging of the na&#239;ve mouse visual projection and for repetitive and longitudinal in vivo studies of optic nerve degeneration associated with acute optic nerve crush injury and chronic optic nerve degeneration in knock-out mice (p50KO).

The rodent visual system encompasses retinal ganglion cells and their axons that form the optic nerve to enter thalamic and midbrain centers, and ...

Neuroscience

Visual Evoked Potential Recording in a Rat Model of Experimental Optic Nerve Demyelination

The visual evoked potential (VEP) recording is widely used in clinical practice to assess the severity of optic neuritis in its acute phase, and to monitor the disease course in the follow-up period. Changes in the VEP parameters closely correlate with pathological damage in the optic nerve. This protocol provides a detailed description about the rodent model of optic nerve microinjection, in which a partial demyelination lesion is produced in the optic nerve. VEP recording techniques are also discussed. Using skull implanted electrodes, we are able to acquire reproducible intra-session and between-session VEP traces. VEPs can be recorded on individual animals over a period of time to assess the functional changes in the optic nerve longitudinally. The optic nerve demyelination model, in conjunction with the VEP recording protocol, provides a tool to investigate the disease processes associated with demyelination and remyelination, and can potentially be employed to evaluate the effects of new remyelinating drugs or neuroprotective therapies.

Focal demyelination is induced in the optic nerve using lysolecithin microinjection. Visual evoked potentials are recorded via skull electrodes implanted over the visual cortex to examine the signal conduction along the visual pathway in vivo. This protocol details the surgical procedures underlying electrode implantation and optic nerve microinjection.

The visual evoked potential (VEP) recording is widely used in clinical practice to assess the severity of optic neuritis in its acute phase, and to ...

Induction of Paralysis and Visual System Injury in Mice by T Cells Specific for Neuromyelitis Optica Autoantigen Aquaporin-4

While it is recognized that aquaporin-4 (AQP4)-specific T cells and antibodies participate in the pathogenesis of neuromyelitis optica (NMO), a human central nervous system (CNS) autoimmune demyelinating disease, creation of an AQP4-targeted model with both clinical and histologic manifestations of CNS autoimmunity has proven challenging. Immunization of wild-type (WT) mice with AQP4 peptides elicited T cell proliferation, although those T cells could not transfer disease to na&#239;ve recipient mice. Recently, two novel AQP4 T cell epitopes, peptide (p) 135-153 and p201-220, were identified when studying immune responses to AQP4 in AQP4-deficient (AQP4-/-) mice, suggesting T cell reactivity to these epitopes is normally controlled by thymic negative selection. AQP4-/- Th17 polarized T cells primed to either p135-153 or p201-220 induced paralysis in recipient WT mice, that was associated with predominantly leptomeningeal inflammation of the spinal cord and optic nerves. Inflammation surrounding optic nerves and involvement of the inner retinal layers (IRL) were manifested by changes in serial optical coherence tomography (OCT). Here, we illustrate the approaches used to create this new in vivo model of AQP4-targeted CNS autoimmunity (ATCA), which can now be employed to study mechanisms that permit development of pathogenic AQP4-specific T cells and how they may cooperate with B cells in NMO pathogenesis.

Here, we present a protocol to induce paralysis and opticospinal inflammation by transfer of aquaporin-4 (AQP4)-specific T cells from AQP4-/- mice into WT mice. In addition, we demonstrate how to use serial optical coherence tomography to monitor visual system dysfunction.

While it is recognized that aquaporin-4 (AQP4)-specific T cells and antibodies participate in the pathogenesis of neuromyelitis optica (NMO), a human ...

Immunology and Infection

Bioluminescence and Near-infrared Imaging of Optic Neuritis and Brain Inflammation in the EAE Model of Multiple Sclerosis in Mice

Experimental autoimmune encephalomyelitis (EAE) in SJL/J mice is a model for relapsing-remitting multiple sclerosis (RRMS). Clinical EAE scores describing motor function deficits are basic readouts of the immune-mediated inflammation of the spinal cord. However, scores and body weight do not allow for an in vivo assessment of brain inflammation and optic neuritis. The latter is an early and frequent manifestation in about 2/3 of MS patients. Here, we show methods for bioluminescence and near-infrared live imaging to assess EAE evoked optic neuritis, brain inflammation, and blood-brain barrier (BBB) disruption in living mice using an in vivo imaging system. A bioluminescent substrate activated by oxidases primarily showed optic neuritis. The signal was specific and allowed the visualization of medication effects and disease time courses, which paralleled the clinical scores. Pegylated fluorescent nanoparticles that remained within the vasculature for extended periods of time were used to assess the BBB integrity. Near-infrared imaging revealed a BBB leak at the peak of the disease. The signal was the strongest around the eyes. A near-infrared substrate for matrix metalloproteinases was used to assess EAE-evoked inflammation. Auto-fluorescence interfered with the signal, requiring spectral unmixing for quantification. Overall, bioluminescence imaging was a reliable method to assess EAE-associated optic neuritis and medication effects and was superior to the near-infrared techniques in terms of signal specificity, robustness, ease of quantification, and cost.

We show a technique for in vivo live bioluminescence and near-infrared imaging of optic neuritis and encephalitis in the experimental autoimmune encephalomyelitis (EAE) model for multiple sclerosis in SJL/J mice.

Experimental autoimmune encephalomyelitis (EAE) in SJL/J mice is a model for relapsing-remitting multiple sclerosis (RRMS). Clinical EAE scores describing ...

Using Optical Coherence Tomography and Optokinetic Response As Structural and Functional Visual System Readouts in Mice and Rats

Optical coherence tomography (OCT) is a fast, non-invasive, interferometric technique allowing high-resolution retinal imaging. It is an ideal tool for the investigation of processes of neurodegeneration, neuroprotection and neuro-repair involving the visual system, as these often correlate well with retinal changes. As a functional readout, visually evoked compensatory eye and head movements are commonly used in experimental models involving the visual function. Combining both techniques allows a quantitative in vivo investigation of structure and function, which can be used to investigate the pathological conditions or to evaluate the potential of novel therapeutics. A great benefit of the presented techniques is the possibility to perform longitudinal analyses allowing the investigation of dynamic processes, reducing variability and cuts down the number of animals needed for the experiments. The protocol described aims to provide a manual for acquisition and analysis of high quality retinal scans of mice and rats using a low cost customized holder with an option to deliver inhalational anesthesia. Additionally, the proposed guide is intended as an instructional manual for researchers using optokinetic response (OKR) analysis in rodents, which can be adapted to their specific needs and interests.

A detailed protocol for the assessment of structural and visual readouts in rodents by optical coherence tomography and optokinetic response is presented. The results provide valuable insights for ophthalmologic as well as neurologic research.

Optical coherence tomography (OCT) is a fast, non-invasive, interferometric technique allowing high-resolution retinal imaging. It is an ideal tool for ...

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Recently, the isolated-check visual evoked potential (icVEP) technique was designed and has been reported to detect glaucomatous damage earlier and faster. It creates low spatial frequency/high temporal frequency bright stimuli and records cortical activity initiated primarily by afferents in the magnocellular ON pathway. This pathway contains neurons with larger volumes and axonal diameters, and it is preferentially damaged in early glaucoma, which can result in visual field loss. The study presented here uses standard operative procedures (SOP) of icVEP to obtain reliable results. It can detect visual function loss using a signal-to-noise ratio (SNR) corresponding to the defects of retinal nerve fiber layer (RNFL) in early stage open-angle glaucoma (OAG). A setting of 10 Hz and condition of 15% positive-contrast (bright) are selected to differentiate OAG patients and control subjects, with each check containing eight runs. Each run persists for 2 s (for 20 total cycles). A flowchart is constructed, which consists of pupil size and intraocular pressure over a 30 min rest period before each examination. Additionally, the testing order of eyes is performed to obtain reliable electroencephalographic signals. VEPs are recorded and analyzed automatically by software, and SNRs are derived based on a multivariate statistic. An SNR of &#8804; 1 is considered abnormal. A receiver-operating-characteristic (ROC) curve is applied to analyze the accuracy of group classification. Then, the SOP is applied in a cross-sectional study, showing that icVEP can detect glaucomatous visual function abnormality in the central visual field in the form of SNR. This value also correlates with the thickness thinning of RNFL and produces high classification accuracy for early stage OAG. Thus, it serves as a useful and objective diagnostic technology for the early detection of glaucoma.

The isolated-check visual evoked potential (icVEP) method is implemented here to assess the magnocellular ON pathway that is initially damaged in glaucoma. The study shows standard operative procedures using icVEP to obtain reliable results. It is proved to serve as a useful objective diagnosing technology for the early detection of glaucoma.

Recently, the isolated-check visual evoked potential (icVEP) technique was designed and has been reported to detect glaucomatous damage earlier and ...

Histological Staining of Spinal Cord for Assessing EAE Disease Severity

Scoring Central Nervous System Inflammation, Demyelination, and Axon Injury in Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a common immune-based model of multiple sclerosis (MS). This disease can be induced in rodents by active immunization with protein components of the myelin sheath and Complete Freund&#39;s adjuvant (CFA) or by the transfer of myelin-specific T effector cells from rodents primed with myelin protein/CFA into na&#239;ve rodents. The severity of EAE is typically scored on a 5-point clinical scale that measures the degree of ascending paralysis, but this scale is not optimal for assessing the extent of recovery from EAE. For example, clinical scores remain high in some EAE models (e.g., myelin oligodendrocyte glycoprotein [MOG] peptide-induced model of EAE) despite the resolution of inflammation. Thus, it is important to complement clinical scoring with histological scoring of EAE, which also provides a means to study the underlying mechanisms of cellular injury in the central nervous system (CNS).
Here, a simple protocol is presented to prepare and stain spinal cord and brain sections from mice and to score inflammation, demyelination, and axonal injury in the spinal cord. The method for scoring leukocyte infiltration in the spinal cord can also be applied to score brain inflammation in EAE. A protocol for measuring soluble neurofilament light (sNF-L) in the serum of mice using a Small Molecule Assay (SIMOA) assay is also described, which provides&#160;feedback on the extent of overall CNS injury in live mice.

Author Spotlight: Unveiling the Pathway Linking Obesity to Autoimmune Inflammation in Multiple Sclerosis 

Experimental autoimmune encephalomyelitis (EAE) serves as an animal model of multiple sclerosis. This article describes an approach for scoring spinal cord inflammation, demyelination, and axonal injury in EAE. Additionally, a method to quantify soluble neurofilament light levels in the mice serum is presented, facilitating the assessment of axonal injury in live mice.

Experimental autoimmune encephalomyelitis (EAE) is a common immune-based model of multiple sclerosis (MS). This disease can be induced in rodents by ...

In Vivo Methods to Assess Retinal Ganglion Cell and Optic Nerve Function and Structure in Large Animals

The optic nerve collects axons signals from the retinal ganglion cells and transmits visual signal to the brain. Large animal models of optic nerve injury are essential for translating novel therapeutic strategies from rodent models to clinical application due to their closer similarities to humans in size and anatomy. Here we describe some in vivo methods to evaluate the function and structure of the retinal ganglion cells (RGCs) and optic nerve (ON) in large animals, including visual evoked potential (VEP), pattern electroretinogram (PERG) and optical coherence tomography (OCT). Both goat and non-human primate were employed in this study. By presenting these in vivo methods step by step, we hope to increase experimental reproducibility among different labs and facilitate the usage of large animal models of optic neuropathies.

In Vivo Methods to Assess Retinal Ganglion Cell and Optic Nerve Function and Structure in Large Animals

Here we demostrate several in vivo tests (flash visual evoked potential, pattern electroretinogram and optic coherence tomography) in goat and rhesus macaque to understand the structure and function of the optic nerve and its neurons.

The optic nerve collects axons signals from the retinal ganglion cells and transmits visual signal to the brain. Large animal models of optic nerve injury ...

A New Optokinetic Testing Method to Measure Rat Vision

Optokinetic nystagmus (OKN) is a reflexive eye movement initiated by the motion of visual stimuli in the field of vision. The head-tracking movement associated with OKN is commonly used as a measure of visual function in rodents. To record OKN responses in normal and experimental rats, a simple and inexpensive apparatus has been developed. This setup uses two tablet screens to display the OKN visual stimulus consisting of high contrast black and white stripes generated using the OKN Stripes Visualization Web Application, a freely available software. The rat is placed inside a clear Plexiglass holder that limits&#160;movement so that the&#160;rat&#39;s head continuously faces the OKN display screen. The position of the rat holder can be changed to adjust the distance between the rat and the display screen. A micro-camera positioned above the rat holder is used to record the rat&#39;s visual activities. These recordings can be used for quantitative assessments. Based on the presence or absence of clear head-tracking, the OKN responses at different spatial frequencies can be determined. The collected data demonstrates a novel technique for reliable measurement of visual acuity in normal and retinal degenerate rats.

The Optokinetic Nystagmus (OKN) behavioral testing method is used for the assessment of visual acuity in rodents. Here a simple method is demonstrated that can be easily set up in research laboratories for a reliable assessment of visual function in both normal and experimental rats.

Optokinetic nystagmus (OKN) is a reflexive eye movement initiated by the motion of visual stimuli in the field of vision. The head-tracking movement ...

Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients

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Chapters in this video

Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats

In vivo Imaging of Optic Nerve Fiber Integrity by Contrast-Enhanced MRI in Mice

Visual Evoked Potential Recording in a Rat Model of Experimental Optic Nerve Demyelination

Induction of Paralysis and Visual System Injury in Mice by T Cells Specific for Neuromyelitis Optica Autoantigen Aquaporin-4

Bioluminescence and Near-infrared Imaging of Optic Neuritis and Brain Inflammation in the EAE Model of Multiple Sclerosis in Mice

Using Optical Coherence Tomography and Optokinetic Response As Structural and Functional Visual System Readouts in Mice and Rats

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Scoring Central Nervous System Inflammation, Demyelination, and Axon Injury in Experimental Autoimmune Encephalomyelitis

In Vivo Methods to Assess Retinal Ganglion Cell and Optic Nerve Function and Structure in Large Animals

A New Optokinetic Testing Method to Measure Rat Vision