DCED State of Pennsylvania

1. Course Construction
<ol>
	<li>Install course floor. Course dimensions are 40 ft long by 7 ft wide consisting of 280 1 ft2 portable floor tiles (beige event floor tiles). Place with black trim around perimeter only (Figure 1).</li>
	<li>Paint the adjacent walls to match the floor tiles creating a somewhat monochromatic environment. Colors we used with greyscale values are provided (Table 5). If the specific colors are not available, we recommend taking a tile to a hardware store for color matching.</li>
	<li>Install lighting according to the lighting template (Figure 1). Connect lights to dimmer switch.</li>
	<li>Paint obstacles according to painting instructions (Figure 2).</li>
</ol>
2. Prepare Testing Area
<ol>
	<li>Adjust lighting to desired condition and check with light meter at the beginning, middle, and end of the hallway containing the course.</li>
	<li>Make sure that the video camera is set to record and that placement of the camera is appropriate to capture the subjects as they walk through the course. We recommend a ceiling mount or alternatively the camera can be hand held.</li>
</ol>
3. Record Preferred Walking Speed PWS
<ol>
	<li>Position subject in center of walkway (course column &#34;D&#34;). Note: toes should be behind border of walkway. Read instructions to the subject (Figure 3).</li>
	<li>Begin stopwatch once foot crosses black border and onto pathway. Stop time once foot crosses black border at other end of walkway. Record time as PWS1. Turn subject around and repeat procedure in opposite direction. Record time as PWS2. Average PWS1 and PWS2 and record as final PWS.</li>
</ol>
4. Obstacle Course Navigation
<ol>
	<li>From the randomization scheme, set up the first course (Figure 4). Floor tiles should be used as the grid upon which the obstacles are mapped. Refer to the provided diagram for correct mapping of the obstacles. It is helpful to number the tiles along the vertical and horizontal axis with an indelible marker to permit easy placement of the obstacles. It is also helpful to label the obstacles according to the provided diagrams in an inconspicuous location.</li>
	<li>Guide subject to start of 40 ft walkway. Read instructions to the subject (Figure 3). Subject should be positioned in center of walkway (column &#34;D&#34;) with toes behind border. Begin stopwatch once foot crosses black border and onto pathway. Stop time once foot crosses black border at other end of walkway. Record this time as Course Speed (CS).</li>
	<li>Record when obstacles are hit, grading the severity of the hit on a 3 point scale. The course run should be videotaped for later confirmation by an independent observer.</li>
</ol>
5. Obstacle Identification
<ol>
	<li>Upon completion of course navigation task, turn subject around to face the course and position at center of course (column D). Note: make sure that any obstacles that require repositioning in order to view correct color from end of course is rotated. Read instructions to subject (Figure 3). At this time the first object identification task will be administered. Ask the subject to turn around and tell the Research Assistant the total number of objects they can discern within 30 sec. This number should be recorded.</li>
	<li>Tell the subject to walk back through the course and point to each obstacle they can see. It does not matter if they collide with the obstacle. The number of obstacles they can see is recorded. It is helpful to record which obstacles they are able to detect. This is not timed.</li>
</ol>
Items 4 and 5 should be repeated for each course version that is run.

<ol>
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The authors have nothing to disclose.

We describe an indoor, portable, easily reproducible, and relatively inexpensive course that can be used to evaluate obstacle avoidance in persons who are blind or have low vision. Most current obstacle course designs and tests (i.e. TUGS) are difficult to compare across sites and observers, or are permanent instillations which cannot readily be performed at alternate locations16,17,30. Our goal was to create a course that could be standardized for use at different locations and with different observe...

Low vision rehabilitation assessments must determine whether intervention results in improvement in function. Performance metrics typically involve computer based&#160;reading&#160;or functional assessments1-9&#160;as well as quality of life questionnaires10-15. Being able to also assess the low vision patient&#39;s ability to navigate around obstacles might also provide clues to functional improvements18&#160;particularly in the case of artificial vision devices. Geruschat et al. recently published navigation outcomes with a retinal implant chip, highlighting the need for a standard metric in this area17. Currently there are no widely accepted, objective, validated, and comprehensive standards for determining capacity for obstacle avoidance.
Development of a functional test that would correlate to navigation performance for persons with low vision or &#34;ultra low vision&#34; as produced by artificial vision would be desirable, but has remained an elusive goal. The burgeoning field of artificial vision devices such as retinal implant chips18-24&#160;or sensory substitution devices such as the BrainPort 25&#160;and The vOICe26, necessitates a test of obstacle avoidance that might correlate to increased navigational abilities conferred by these devices. Such an assessment would not only allow subjects to understand their own limitations as they traverse their surroundings, but might provide a means for measuring improvement with orientation and mobility training or between iterations of vision enhancement prototype devices. Ideally, there might be some ability to assess an individual&#39;s risk for fall accidents27.
Our goal was to create an obstacle course that would be useful for evaluation of navigation ability in patients using artificial vision devices and transferrable to the field of low vision in general. A review of the published literature on obstacle courses and visual impairment was undertaken using the PubMed database. There have been numerous attempts at creating standardized obstacle courses16,17,28-31,34. Most of these are not portable in the sense that it would be difficult to exactly reproduce the setting, particularly for outdoor courses. Maguire et al. describe obstacle course which is used to show mobility performance in patients with Leber&#39;s Congenital Amaurosis. This course has the benefit of being portable and small, but it is not clear whether different iterations have been made available to prevent memorization effects, nor are there any provisions for obstacles which are not on the floor, texture changes, or stepovers. Leat provides an incisive description of potential pitfalls in designing a course and puts forth a description of an outdoor course which unfortunately would not be able to be reproduced exactly in an alternative location30. Velikay-Parel et al. described a mobility test for use with retinal implant chips. This design had the benefit of being portable and simple to execute. While this course could be reproduced at an alternative site, no specific details on course construction are provided. Moreover, and more concerning was that they showed the learning effect reached asymptotic levels due to course familiarity, therefore being able to prevent course memorization altogether might eliminate the concern for loss of learning effect over time18. None of the courses described so far have been widely adopted by the low-vision or rehabilitation communities.
The authors subsequently consulted with a team of six low vision occupational therapists and orientation and mobility specialists from the Western Pennsylvania School for Blind Children (Pittsburgh, PA) and the Blind and Vision Services Rehabilitation of Pittsburgh (Homestead, PA) regarding proposed course design. Desirable attributes of a functional obstacle course identified included: Portability for easy assembly/disassembly and storage, flexibility to test under both dim and bright lighting conditions, and to mirror &#34;real life&#34; situations by including obstacles that represent objects in a patient&#39;s home environment that are sturdy enough to withstand repeated collision while being ductile in order to prevent patient injury. In addition it was deemed necessary to have several types of environments designed in such as way so that when administered in a randomized order prevents course memorization. In addition, the course should demonstrate reproducible results in multiple settings, have strong inter and intra rater reliability and be an objective measure of spatial awareness.
The culmination of this effort was development of an obstacle course which could reasonably be expected to be reproduced in a standard institutional hallway. The course is designed to test different skill sets, all important for navigation. Each level of the course attempts to focus several particular types of obstacles encountered in everyday navigation activities. The first course evaluates the ability to navigate through relatively high contrast targets that are all placed on the floor, but requires a large number of turns. The second course evaluates the ability to navigate through obstacles that are both high and low contrast, floor texture changes, and objects suspended in air. The final course evaluates the ability to navigate Styrofoam obstacles that are low contrast, surface glare changes on the floor, the addition of nonStyrofoam obstacles (fabric), floor tile color changes, obstacles that must be stepped over, and obstacles that are not on the floor. The courses are labeled 1, 2, and 3 for ease of labeling, but this designation should not be construed as increasing in level of difficulty. Within each level, there are three versions of the course, which can be randomized to prevent course memorization.

<table><tbody><tr><td>Event Floor Tiles, beige</td><td>Snaplock Industries, Salt Lake City UT</td><td></td><td>Beige</td></tr><tr><td>Event Floor Tiles, black trim</td><td>Snaplock Industries, Salt Lake City UT</td><td></td><td>Male loop</td></tr><tr><td>Event Floor Tiles, black trim</td><td>Snaplock Industries, Salt Lake City UT</td><td></td><td>Female loop</td></tr><tr><td>Event Floor Tiles, Edging</td><td>Snaplock Industries, Salt Lake City UT</td><td></td><td>Black</td></tr><tr><td>Wall Paint: Satin Premium Plus Internal Satin Enamel Custom Color Match</td><td>Behr, Inc Santa Ana CA</td><td>custom</td><td>Greyscale value = 45</td></tr><tr><td>Obstacle paint</td><td>Valspar Paints, Wheeling, IL</td><td>DuJour (#70002-6)</td><td>DuJour Greyscale value = 15</td></tr><tr><td>Obstacle paint</td><td>Valspar Paints, Wheeling, IL</td><td>Fired Earth (#6011-1)</td><td>Fired Earth Greyscale value = 95</td></tr><tr><td>Styrofoam obstacles</td><td>Universal Foam Products, Orlando CA</td><td>custom</td><td></td></tr><tr><td>Con-Tact Brand Contact Paper</td><td>Lowe&#039;s Home Improvement</td><td>639982</td><td>Solid Black</td></tr><tr><td>Con-Tact Brand Contact Paper</td><td>Lowe&#039;s Home Improvement</td><td>615542</td><td>Stainless Steel</td></tr><tr><td>Con-Tact Brand Contact Paper</td><td>Lowe&#039;s Home Improvement</td><td>614416</td><td>Solid White</td></tr><tr><td>3 ft x 6 ft Standard tuff Olefin Floor Mat</td><td>Commercial Mats and Rubber A Division of Georgia Mills Direct Saratoga Springs, NY</td><td></td><td>Charcoal</td></tr><tr><td>3 ft x 6 ft Standard tuff Olefin Floor Mat</td><td>Commercial Mats and Rubber A Division of Georgia Mills Direct Saratoga Springs, NY</td><td></td><td>Smoke</td></tr><tr><td>Fisher Scientific Traceable Dual Range Light Meter</td><td>Fisher Scientific</td><td>06-662-63</td><td>International Light, Newburyport MA, USA</td></tr><tr><td>5 1/2 in Clamp Light</td><td>Lowe&#039;s Home Improvement</td><td>203198</td><td></td></tr><tr><td>GE 65-Watt indoor incandescent flood light bulb</td><td>Lowe&#039;s Home Improvement</td><td>163209</td><td></td></tr></tbody></table>

a standardized obstacle course for assessment of visual function in ultra low vision and artificial vision

We describe an indoor, portable, standardized course that can be used to evaluate obstacle avoidance in persons who have ultralow vision. Six sighted controls and 36 completely blind but otherwise healthy adult male (n=29) and female (n=13) subjects (age range 19-85 years), were enrolled in one of three studies involving testing of the BrainPort sensory substitution device. Subjects were asked to navigate the course prior to, and after, BrainPort training. They completed a total of 837 course runs in two different locations. Means and standard deviations were calculated across control types, courses, lights, and visits. We used a linear mixed effects model to compare different categories in the PPWS (percent preferred walking speed) and error percent data to show that the course iterations were properly designed. The course is relatively inexpensive, simple to administer, and has been shown to be a feasible way to test mobility function. Data analysis demonstrates that for the outcome of percent error as well as for percentage preferred walking speed, that each of the three courses is different, and that within each level, each of the three iterations are equal. This allows for randomization of the courses during administration.
Abbreviations: 
preferred walking speed (PWS) 
course speed (CS) 
percentage preferred walking speed (PPWS)

Subjects
Six sighted blindfolded, sighted, and 36 completely blind but otherwise healthy adult (age range 19-85 years), male (n=29) and female (n=13) subjects were enrolled in one of three studies involving testing of the BrainPort sensory substitution device (Wicab, Madison WI). All studies were approved by the University of Pittsburgh IRB and all subjects signed an approved informed consent document. All studies were a within subjects, repeated measures design such that each subject acted as th...

Watch this Scientific Journal Video about A Standardized Obstacle Course for Assessment of Visual Function in Ultra Low Vision and Artificial Vision at JoVE.com

A Standardized Obstacle Course for Assessment of Visual Function in Ultra Low Vision and Artificial Vision

We describe an indoor, portable, standardized course that can be used to evaluate obstacle avoidance in persons who have ultralow vision. The course is relatively inexpensive, simple to administer, and has been shown to be reliable and reproducible.

We describe an indoor, portable, standardized course that can be used to evaluate obstacle avoidance in persons who have ultralow vision. Six sighted ...

a-standardized-obstacle-course-for-assessment-visual-function-ultra

Research

JoVE Journal

Medicine

13.0K Views.  University of Pittsburgh. We describe an indoor, portable, standardized course that can be used to evaluate obstacle avoidance in persons who have ultralow vision. The course is relatively inexpensive, simple to administer, and has been shown to be reliable and reproducible.

Video: A Standardized Obstacle Course for Assessment of Visual Function in Ultra Low Vision and Artificial Vision

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.

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 ...

Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition

Macular degeneration typically results in heterogeneous binocular central visual defects. Currently available approaches to assess central visual field, like the microperimetry, can test only one eye at a time. Therefore, they cannot explain how the defects in each eye affect the binocular interaction and real-world function. Dichoptic stimulus presentation with a gaze-controlled system could provide a reliable measure of monocular/binocular visual fields. However, dichoptic stimulus presentation and simultaneous eye-tracking are challenging because optical devices of instruments that present stimulus dichoptically (e.g., haploscope) always interfere with eye-trackers (e.g., infrared video-based eye-trackers). Therefore, the goals were 1) to develop a method for dichoptic stimulus presentation with simultaneous eye-tracking, using 3D-shutter glasses and 3D-ready monitors, that is not affected by interference and 2) to use this method to develop a protocol for assessing central visual field in subjects with central vision loss. The results showed that this setup provides a practical solution for reliably measuring eye-movements in dichoptic viewing condition. In addition, it was also demonstrated that this method can assess gaze-controlled binocular central visual field in subjects with central vision loss.

Presented here is a protocol for assessing binocular eye movements and gaze-controlled central visual field screening in participants with central vision loss.

Macular degeneration typically results in heterogeneous binocular central visual defects. Currently available approaches to assess central visual field, ...

Behavior

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 ...

A Simple Behavioral Assay for Testing Visual Function in Xenopus laevis

Measurement of the visual function in the tadpoles of the frog, Xenopus laevis, allows screening for blindness in live animals. The optokinetic response is a vision-based, reflexive behavior that has been observed in all vertebrates tested. Tadpole eyes are small so the tail flip response was used as alternative measure, which requires a trained technician to record the subtle response. We developed an alternative behavior assay based on the fact that tadpoles prefer to swim on the white side of a tank when placed in a tank with both black and white sides. The assay presented here is an inexpensive, simple alternative that creates a response that is easily measured. The setup consists of a tripod, webcam and nested testing tanks, readily available in most Xenopus laboratories. This article includes a movie showing the behavior of tadpoles, before and after severing the optic nerve. In order to test the function of one eye, we also include representative results of a tadpole in which each eye underwent retinal axotomy on consecutive days. Future studies could develop an automated version of this assay for testing the vision of many tadpoles at once.

A Simple Behavioral Assay for Testing Visual Function in Xenopus laevis

Xenopus laevis tadpoles prefer swimming on the white side of a black/white tank. This behavior is guided by their vision. Based on this behavior, we present a simple assay to test the visual function of tadpoles.

Measurement of the visual function in the tadpoles of the frog, Xenopus laevis, allows screening for blindness in live animals. The optokinetic response ...

Neuroscience

An Automated Assessment of Visual Acuity in Infants and Toddlers

An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System

Visual acuity measurement is an important visual function test to perform in infancy and childhood. However, accurate visual acuity measurement in infants is difficult because of deficiencies in their communication ability. This paper presents a novel automated method to assess visual acuity in children (5-36 months old). This method, the automated acuity card procedure (AACP), uses a webcam for eye tracking and recognizes children's watching behaviors automatically. A two-choice preferential-looking test is performed when the tested child watches the visual stimuli shown on a high-resolution digital display screen. When the tested child watches the stimuli, their facial pictures are recorded by the webcam. These pictures are used by the set computer program to analyze their watching behavior. With this procedure, the child's eye movement responses to different stimuli are measured, and their visual acuity is assessed without communication. By comparing the results with grating acuity obtained by Teller Acuity Cards (TACs), AACP performance is deemed comparable to that of TACs.

Author Spotlight: An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System  

In this paper, we present a novel automated method for assessing visual acuity in infants and toddlers by using an eye-tracking system.

Visual acuity measurement is an important visual function test to perform in infancy and childhood. However, accurate visual acuity measurement in infants ...

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 ...

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes

Through the purposeful stimulation and recording of eye movements, the fundamental characteristics of the underlying neural mechanisms of eye movements can be observed. VisualEyes2020 (VE2020) was developed based on the lack of customizable software-based visual stimulation available for researchers that does not rely on motors or actuators within a traditional haploscope. This new instrument and methodology have been developed for a novel haploscope configuration utilizing both eye tracking and autorefractor systems. Analysis software that enables the synchronized analysis of eye movement and accommodative responses provides vision researchers and clinicians with a reproducible environment and shareable tool. The Vision and Neural Engineering Laboratory&#39;s (VNEL) Eye Movement Analysis Program (VEMAP) was established to process recordings produced by VE2020&#39;s eye trackers, while the Accommodative Movement Analysis Program (AMAP) was created to process the recording outputs from the corresponding autorefractor system. The VNEL studies three primary stimuli: accommodation (blur-driven changes in the convexity of the intraocular lens), vergence (inward, convergent rotation and outward, divergent rotation of the eyes), and saccades (conjugate eye movements). The VEMAP and AMAP utilize similar data flow processes, manual operator interactions, and interventions where necessary; however, these analysis platforms advance the establishment of an objective software suite that minimizes operator reliance. The utility of a graphical interface and its corresponding algorithms allow for a broad range of visual experiments to be conducted with minimal required prior coding experience from its operator(s).

VisualEyes2020 (VE2020) is a custom scripting language that presents, records, and synchronizes visual eye movement stimuli. VE2020 provides stimuli for conjugate eye movements (saccades and smooth pursuit), disconjugate eye movements (vergence), accommodation, and combinations of each. Two analysis programs unify the data processing from the eye tracking and accommodation recording systems.

Through the purposeful stimulation and recording of eye movements, the fundamental characteristics of the underlying neural mechanisms of eye movements ...

Bioengineering

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 ...

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 ...

Assessing Vision via Shape Recognition in Random Dot Kinematograms

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes

The standard visual acuity measurements rely on stationary stimuli, either letters (Snellen charts), vertical lines (vernier acuity) or grating charts, processed by those regions of the visual system most sensitive to the stationary stimulation, receiving visual input from the central part of the visual field. Here, an acuity measurement is proposed based on discrimination of simple shapes, that are defined by motion of the dots in the random dot kinematograms (RDK) processed by visual regions sensitive to motion stimulation and receiving input also from the peripheral visual field. In the motion-acuity test, participants are asked to distinguish between a circle and an ellipse, with matching surfaces, built from RDKs, and separated from the background RDK either by coherence, direction, or velocity of dots. The acuity measurement is based on ellipse detection, which with every correct response becomes more circular until reaching the acuity threshold. The motion-acuity test can be presented in negative contrast (black dots on white background) or in positive contrast (white dots on black background). The motion defined shapes are located centrally within 8 visual degrees and are surrounded by RDK background. To test the influence of visual peripheries on centrally measured acuity, a mechanical narrowing of the visual field to 10 degrees is proposed, using opaque goggles with centrally located holes. This easy and replicable narrowing system is suitable for MRI protocols, allowing further investigations of the functions of the peripheral visual input. Here, a simple measurement of shape and motion perception simultaneously is proposed. This straightforward test assesses vision impairments depending on the central and peripheral visual field inputs. The proposed&#160;motion-acuity test advances the capability of standard tests to reveal spare or even strengthened vision functions in patients with injured visual system, that until now remained undetected.

Author Spotlight: Assessment of Visual Acuity in Central Vision Loss Through Motion-Based Peripheral Vision Testing

A novel motion-based acuity test that allows the assessment of central and peripheral visual processing in low-vision and healthy individuals, along with goggles limiting peripheral vision compatible with MRI protocols, are described here. This method offers a comprehensive vision assessment for functional impairments and dysfunctions of the visual system.

The standard visual acuity measurements rely on stationary stimuli, either letters (Snellen charts), vertical lines (vernier acuity) or grating charts, ...

A Standardized Obstacle Course for Assessment of Visual Function in Ultra Low Vision and Artificial Vision

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Rozdziały w tym wideo

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

Assessing Binocular Central Visual Field and Binocular Eye Movements in a Dichoptic Viewing Condition

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

A Simple Behavioral Assay for Testing Visual Function in Xenopus laevis

An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System

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

Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes

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

A New Optokinetic Testing Method to Measure Rat Vision

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes