Examining Disparity Driven Vergence as a Potential Diagnostic Test for Mild Traumatic Brain Injury (mTBI)
Phase: NA
Conditions: Mild Traumatic Brain Injury
Sponsor: University of Miami

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Study #: 20180058Effective Date: 6/23/2020 
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Examining disparity driven vergence as a potential 
diagnostic test for mild traumatic brain injury (mTBI) 
 
 
 
 
 
 
 
 
 
 
 
 
 
NCT Number NCT03529799 
 
 
 
 
 
 

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1) 
Protocol Title 
Examining disparity driven vergence as a potential diagnostic test for mild traumatic brain 
injury (mTBI) 
2) 
IRB Review History* 
None. 
3) 
Objectives* 
Specific Aim 1 (SA1): Determine the validity and safety of disparity driven vergence testing with 
a portable goggle system using a pseudorandom ternary sequence of frequencies on a group of 
normal subjects. 
Specific Aim 2 (SA2): Determine the vergence testing control values using a portable goggle 
system using a pseudorandom ternary sequence of frequencies on a group of normal subjects. 
Specific Aim 3 (SA3): Determine the vergence testing values with a portable goggle system using 
a pseudorandom ternary sequence of frequencies on a group of subjects with history of mild 
traumatic brain injury and compare this to values in normal subjects. 
4) 
Background 
 
Vergence eye movements for focusing on objects include either convergence, the coordinated movement of 
both eyes towards the midline, or divergence, the coordination movement of both eyes towards the periphery. 
These eye movements are thought to be controlled by complex neurophysiological mechanisms that can be 
susceptible to damage by traumatic brain injury. Known involved areas in vergence include the oculomotor 
nucleus, cerebellum, and visual association cortex (Conn 2016), all of which can sustain damage during head 
trauma. 
 
Modern balance function assessment includes electronystagmography and more recently, videonystagmography 
(ENG/VNG) to assess vertigo, dizziness, and imbalance. Additionally, vestibular-evoked myogenic potentials 
(VEMP), rotational testing, and computerized dynamic posturography (CDP) are very useful in evaluating 
multi-sensory integration of vision, somatosensory, and vestibular system function. VNG records eye 
movements using digital video image technology employing infrared illumination to determine eye position. 
The use of VNG enables simultaneous subjective observation of eye movements together with objective data 
collection and analysis of eye movement waveforms via computer algorithms (Kang 2015). More recently 
vestibular function has been tested in rotational chair devices. These devices utilize VNG goggles and perform 
many of the same tests done in a traditional VNG test but adds tests that involve moving the body (and with the 
body the head) through a variety of motion paradigms. Eye response to these body/head accelerations are 
recorded and abnormalities can be plotted against established norms. This technology is useful but involves a 
large and expensive piece of equipment in a dedicated vestibular lab. As a result, portable devices have been 
developed that perform many of the same functions that the chair performs. Head to head comparisons between 
rotational chair testing and portable vestibulo-ocular reflex gain and phase testing have shown consistent results 
between modalities (Goebel 1995). Portable vestibular testing has thus become a reality, allowing physicians 

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and audiologists the ability to test subjects outside of the typical clinical setting and in a variety of environments 
and conditions. 
 
As such portable devices arise and become available to practitioners, their safety, validity, and efficacy must be 
determined. The portable goggle system, IPAS goggles (Neuro-kinectics, Inc., Pittsburgh, PA), have been 
developed to measure vestibular function and can be used for vergence testing. Current tests of binocular 
disparity driven vergence examine only one frequency (0.1 Hz) and tests at that single frequency may provide 
only limited information in the diagnosis and follow-up of mTBI patients. A greater number of frequencies can 
provide a spectrum of values that may help with this assessment. As testing all of the possible frequencies is not 

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feasible, we propose a pseudorandom ternary sequence approach to frequency distribution during disparity 
driven vergence to allow rapid analysis over a wide range of frequencies. Essentially, a pseudorandom 
frequency distribution can help extrapolate data to a larger frequency data set. We will also be evaluating the 
safety and side effect profile of using the goggles using a medical symptom questionnaire. 
 
 
5) 
Inclusion and Exclusion Criteria 
Inclusion: 
- Aged 18 or older 
- Both females and males 
Exclusion: 
- Central processing disorder 
- Impaired vision without corrective lenses (max 20/60 uncorrected) 
- Moderate to severe hearing loss (>55dB PTA, <50% word identification) 
- Vestibular disorder except for patients recruited for SA3 
- History of ear surgery other than myringotomy with or without tube placement 
- Pregnant women 
- Prisoners 
- Adults unable to consent 

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6) 
Number of Subjects 
60 subjects – 30 normal controls (no mTBI), 30 patients with mTBI. 
7) 
Recruitment Methods 
Normal subjects will be recruited from a pool of patients from a population who are unaffiliated or 
affiliated with University of Miami and meet inclusion criteria and not excluded by exclusion criteria. The 
faculty and students of any University of Miami School will be recruited through advertising in e-mails. 
Emails will be sent to staff and faculty associated with the UM Clinical Research Building (CRB) that 
have their emails stored in the UM Outlook server. Subjects will not be paid to participate. Students and 
staff will be assured that their participation will have no effect on their school performance or grades. 
8) 
mTBI patients will be recruited by convenience from a pool of patients with history of mTBI and no prior 
vestibular disorders that present to the UM CRB Otology Clinic of Dr. Hoffer (SA3)”. The determination 
of their fitness for participation will be made during Dr. Hoffer’s clinical history and physical by asking 
about the history of the head injury and past medical history. 
9) 
Study Timelines 
Vestibular tests will take 15 minutes. 
10) Study Endpoints 
Each participant’s study will be completed when they have completed the vergence testing and other 
vestibular tests. At that point, the data will be de- identified. 
11) Procedures Involved 
The study will be conducted in 2 phases in which each phase comprises of thirty participants. 
In the first phase, thirty participants without mTBI who meet the inclusion criteria and are not excluded 
will be chosen to participate. Participants will sign an informed consent document and undergo 1 session 
of vergence testing, along with a series of vestibular tests. After this testing, the data will be de-identified 
and will only be labeled with sex and age of patient. 
In the second phase, thirty participants with mTBI who meet inclusion criteria and are not excluded will 
be chosen to participate. Participants will sign an informed consent document and undergo 1 session of 
vergence testing, along with a series of vestibular tests. After this testing the data will be de-identified and 
will only be labeled with sex and age of patient. 
After the session, patients will be given a medical symptom/toxicity questionnaire (MSQ) to evaluate for 
any side effects.and the SCAT-5 questionnaire, which will evaluate their current symptoms. 
 
For each vestibular test and data to be obtained, see table below: 
Test 
Activity 
Outcome OR Ordinal Value 
Vergence Pursuit 
Focusing on object 
moving forward and 
backwards 
0 - 100 
Spontaneous 
Nystagmus 
Focusing on an object 
Normal / Abnormal (Side) 
Saccades ~ Horizontal 
Random 
Focusing on objects 
randomly in horizontal 
axis 
Normal / Abnormal (Side) 
Saccades ~ Vertical 
Random 
Focusing on objects 
randomly in vertical axis 
Normal / Abnormal (Side) 
Smooth Pursuit 
Horizontal ~ 0.1 Hz 
Tracking objects in 
horizontal axis, at 0.1 Hz 
Normal / Abnormal (Side) 
Smooth Pursuit 
Horizontal ~0.75 Hz 
Tracking objects in 
horizontal axis, at 0.75 
Hz 
Normal / Abnormal (Side) 
Smooth Pursuit 
Vertical ~0.1 Hz 
Tracking objects in 
vertical axis, at 0.1 Hz 
Normal / Abnormal (Side) 

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Smooth Pursuit 
Vertical ~0.75Hz 
Tracking objects in 
vertical axis, at 0.75 Hz 
Normal / Abnormal (Side) 
Predictive Saccades 
Tracking an object 
moving in predictable 
manner 
Percent (%) Error 
Antisaccade 
Moving eyes away from 
visual onset 
% Error 
OKN (optokinetic 
nystagmus) 
Trapezoidal 
Tracking moving field 
Normal / Abnormal (Side) 
Visual Reaction Time 
Reaction time to object 
Seconds 
Saccades and Reaction 
Time 
Reaction time to off- 
center object 
Seconds 
Auditory Reaction 
Time 
Reaction time to sound 
Seconds 
Self-Paced Saccade 
Saccadic motion 
between two fixed 
targets 
0 - 100 
Pupil Reflex 
Normal light reflex 
0 - 100 
Subjective Visual 
Vertical 
Ability to perceive 
subjective tilt 
0 - 100 
 
12) Data Storage 
The only data to be stored will be the results of the vergence tests and vestibular testing done during the 
two sessions. These results will be tied together by a subject number that will also link to the sex of the 
patient and age of the patient. No PHI that identifies any participant will be kept. All the previously 
described data will be stored on the PI’s computer and used for analyses purposes in room 580 of the 
clinical research building at the University of Miami Medical Center located at 1120 NW 14th street, 5th 
Floor, Miami FL, 33136. It will be password protected, and unique identifiers used for subject protection. 
Data will not be distributed, except in the form of peer-reviewed publication or oral presentation maintain 
the confidentiality of the subjects. 
 
13) Data Management* 
Group mean data and single subject design will be utilized. In the group mean data scoring on each of the 
sessions will be aggregated for each of the specific aims. First session scores will be compared to second 
session scores using standard statistical methods with significance defined as p<0.05. For the single subject 
design the number of subjects for each vestibular tests for each aim who have a significant difference in scores 
between the first and second session will be calculated and analyzed with descriptive statistics. In this way the 
investigators can calculate the difference between each test on the two sessions for each protocol, as it is very 
possible that some tests may be significantly different between the sessions and some tests will not. 

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Data will be stored on the PI’s computer and used for analyses purposes in room 580 of the clinical research 
building at the University of Miami Medical Center located at 1120 NW 14th street, 5th Floor, Miami FL, 
33136. It will be password protected, and unique identifiers used for subject protection. Data will not be 
distributed, except in the form of peer-reviewed publication or oral presentation maintain the 
confidentiality of the subjects. . No PHI that can identify any subjects will be kept beyond the second 
session of testing. 
 
 
14) Withdrawal of Subjects 
Subjects can withdraw at any time but if they withdraw their data will not be used and they will be 
replaced in the study by a new subject. 
 
15) Risks to Subjects 
The risks to the subjects will be minimal. At most, a breach of confidentiality composes the majority of 
the risk. We will take extensive measures to protect confidentiality and to ensure data security. 
 
16) Potential Benefits to Subjects 
Participating in this protocol has no potential benefit to the patients. 
 
17) Vulnerable Populations 
This research does not involve any venerable populations. 
 
18) Sharing of Results with Subjects 
Subjects can see the results of their testing after each session and can see the overall study outcome when 
it is prepared for scholarly presentation and publication. 
 
19) Setting 
All testing will take place in the University of Miami Ear and Hearing Center in the Clinical Research 
Building fifth floor and at a designated site on the University of Miami main campus. 
 
20) Resources Available 
A pair of testing goggles pre-programed to perform the test battery will be available to the investigator. 
 
21) Prior Approvals 
None however these same testing goggles have been used in at least two previously approved protocols at 
the University of Miami. 
 
22) Confidentiality 
We will take exhaustive measures to protect confidentiality at all times. Patients will be assigned unique 
identifier codes and the code will be stored separately from the subject’s records. The records will be 
stored in a locked file in the office of PI-Dr. Hoffer. All computers used in the research will have strong 
password protection and the data will be accessible only to authorized research personnel. Data will be 
stored pursuant to time frames listed under “How Long Do I Keep Research Records” in the Investigator’s 
Manual. 
 
23) Provisions to Protect the Privacy Interests of Subjects 
Subjects will be identified by an alphanumeric code designed to prevent disclosure of their identity. 
Information may be stored in an electronic database which will be secured with a password known only to 
the PI involved in this study. The database will be kept electronically until the conclusion of the study, at 
which time it will be printed and placed in a secure file with all other materials relevant to the study. We 

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will not being accessed any Protected Health Information prior to contact the subject in the clinic and 
neither will be accessed during the course of the proposed research, no medical record required , we will 
collect only name, and DOB 
 
24) Compensation for Research-Related Injury 
None anticipated since this is not more than minimal risk. 
 
25) Economic Burden to Subjects 
None anticipated. 
 
26) Consent Process 
Consent will be obtained by the PI, Sub-I, or study coordinator in the Ear Clinic at the University of Miami 
Medical Center any participants who wish to enroll in the study will be consented at the ENT clinic prior to 
initiating any study procedures. Informed consent will be obtained in writing via the attached documents. 
Participants will be taken into a private room to read the consent form and have any questions regarding the 
study answered by a research team member. 
 
Waiver or Alteration of Consent Process (consent will not be obtained, required information 
will not be disclosed, or the research involves deception) 
No Waiver being sought 
Subjects who are not yet adults (infants, children, teenagers) 
Not part of subject population 
Cognitively Impaired Adults 
Not part of subject population 
Adults Unable to Consent 
Not included in subject population 
 
References 
 
Conn PM. “Vision.” Conn’s Translational Neuroscience. San Diego: Academic Press, 2017. 399-438. 
Mallet HA, Roll A, Arndt P. Disparity-evoked Vergence is Driven by Interocular Correlation. Vision Res., Vol. 
36, No. 18, pp. 2925-2936, 1996. 
 
Kang S, Kim US. Normative Data of Videonystagmography in Young Healthy Adults 
under 40 Years Old. Korean J Ophthalmol 2015;29(2):126-130