Screening Instruments for Measuring Visual Symptoms in Victims of Concussion

Study Overview
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Brief Summary
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Visual dysfunction after mild traumatic brain injury (mTBI) is common but often remain undiscovered during longer periods of time. No valid, reliable and easy-to-use screening instrument for uncovering visual dysfunction exists. Furthermore, it is unknown whether optometric measurements currently used in assessing vision problems are consistent with patients' subjective complaints experienced in everyday life. A better understanding of patients' visual challenges combined with objective measurements, will contribute to a better and more efficient diagnostic investigation and treatment. The aim of this study is to get a better understanding of patients who are suffering from visual dysfunction after mTBI. This understanding will be gained by: developing and validating a questionnaire for uncovering subjective visual complaints in subjects with mTBI. developing eye tracking based screening tools applicable both in- and outside of optometry clinics examining relationships between self-reported data, eye tracking measurements and optometric measurements. The study will consist of N = 200 subjects. N = 100 of the subjects are suffering from mTBI (commotio group). The second group N = 100 is the non-injured group that preferably will consist of relatives to the subjects in the commotio group. The subjects in both groups have to answer the questionnaires regarding subjective visual complains, undergo optometric tests and undergo eye tracking measurements.

Official Title
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Screening Instruments for Measuring Visual Symptoms in Victims of Concussion

Conditions
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Brain Concussion, mTBI - Mild Traumatic Brain Injury

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Individuals may be included if they: are adults between the ages 18 and 65 have been diagnosed with mTBI by a doctor (emergency room or general practice) either exclusively or with another diagnosis e.g. fracture, neck trauma (doesn't apply to control group) can read and understand Danish continuously have symptoms related to trauma ≥ 2 months and ≤ 24 months after trauma origin (doesn't apply to control group) have best corrected visus at 0.8 or better in both eyes at distance and at near have given informed consent and willingness to participate in the study Exclusion Criteria: The following will be exclude if individuals: are diagnosed with one of the following neurological disorders: severe head trauma, brain tumor, Parkinson's disease, multiple sclerosis, dementia are diagnosed with an active psychiatric disorder are diagnosed with one of the following somatic disorders which are unregulated: diabetes mellitus, metabolic disorders have a verified alcohol or drug abuse have amblyopia (that is, two lines difference or more in best corrected visus between the two eyes) have other visual problems such as constant strabismus, a history of strabismus surgery, congenital nystagmus and recognized eye illnesses such as glaucoma, age- related macular degeneration (AMD) have received vision therapy by an optometrist in relation to resent mTBI

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Mild traumatic brain injury group<br>Consist of patients who have been diagnosed with mTBI by a doctor at an emergency room or in general practice. The patients must still have symptoms related to their trauma ≥ 2 months and ≤ 24 months after trauma origin. They must not have received any vision therapy from an optometrist in relation to resent mTBI. | |
| Non-injured group<br>The control group will primarily consist of relatives of the individuals with mTBI, preferably a partner or a sibling. The subjects in the control group have to meet the same inclusion and exclusion criteria as the mTBI group, except that they must not be diagnosed with mild traumatic brain injury. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VISCOM Questionnaire | Development and validation of the VISCOM questionnaire consisting of 42 times and establishing a cut-off score, with the aim of uncovering subjective visual symptoms after mTBI. The patients can score their visual symptoms on a Likert scale from 1-5, where one is never and five is always. The higher score the more severe symptoms. The patient symptom score will be compared to the control group symptom score. | Estimated duration: 20 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Rivermead Post Concussion Symptoms Questionnaire (RPQ) | Valid questionnaire consisting 16 items, assessing symptoms after mTBI. The patients can score their visual symptoms from 1-5, one is not experienced at all and five is a severe problem. The higher score, the more server symptoms. | Estimated duration in total: 5 minutes | 
| Vergence facility | A test of the eyes ability to converge and diverge using a 12 pd base out and 3 pd base in vergence flipper. The result is measured in cycles per minute, using a vertical line of letters 0,4/0,6 ≤ 35 years, and 0,4/1,0 >35 years. | Estimated duration in total: 2 minutes | 
| Fusional vergence at near | A test of the eyes ability to maintain fusion at 0,4 meter using rotary prism, both positive and negative fusional vergence. The result is measured in prism diopters using a vertical line of letters 0,4/0,6. | Estimated duration in total: 2 minutes | 
| Monocular amplitude of accommodation | A test of the eyes ability to accommodate using the Accommodation and Near Point Rule. The result is measured in cm using a vertical line with letters 0,4/0,6 with patients ≤ 35 years. The test is done separately with right and left eye. | Estimated duration in total: 2 minutes | 
| Monocular accommodation facility | A test of the eyes ability to accommodate and relax using a using a ± 2.00 accommodative flipper. The result is measured in cycles per minute, using a vertical line of letters 0,4/0,6 patients ≤ 35 years. | Estimated duration in total: 2 minutes | 
| Horizontal and vertical phoria | A test of the eyes natural alignment or misalignment using Modified Thorington Test measured in prism diopters at 6 meter and 0,4 meter. | Estimated duration in total: 2 minutes | 
| Near point of convergence | A test of the eyes ability to converge using the Accommodation and Near Point Rule. The result is measured in cm using a vertical line with letters 0,4/0,6 ≤ 35 years, and 0,4/1,0 >35 years. The test is repeated twice in the optometry clinic and twice using an eye-tracking setup. | Estimated duration in total: 5 minutes | 
| Saccadic eye movement | A test of the of saccades using 3 test cards and one demonstration card, in the optometry clinic and also using an eye-tracking setup. The result is measured in seconds and errors in total. | Estimated duration in total: 10 minutes | 
| Reaction test | An eye-tracking test of the participant's reaction time for a visual target appearing after a random delay. The result is measured as delay from the target appears to the following reactions: eye movement initiation, target fixation. Additionally, the accuracy of the initial fixation is measured. The test is repeated 24 times with delays drawn from three normal distributions. The delays are identical between participants. | Estimated duration in total: 5 minutes | 
| Pattern test | An eye-tracking test of the participant's ability to follow a moving circular target placed in a grid of identical moving targets. The target's position and direction of movement is indicated before the test is started. The result is measured as average fixation accuracy over the test period. The test is repeated 24 times with varying movement speed, direction, and target size. | Estimated duration in total: 5 minutes | 
| Saccade test | An eye-tracking of the participant's ability to quickly move their eyes between two targets in a given timeframe. The targets are circular and vary in size and position for each test repetition. The result is measured in number of correct saccades between the targets as well as the average fixation error (fixation distance outside target). | Estimated duration in total: 5 minutes | 
| Smooth pursuit test | An eye-tracking of the participant's ability to follow a small circular target's movements across a screen at various speeds and movement patterns. The test is repeated a total of 25 times comprised of 5 movement speeds for each of 5 patterns (horizontal line, vertical line, two diagonal lines, circle). The result is measured as average target deviation, number and duration of blinks, and number and amplitude of saccadic movements. | Estimated duration in total: 5 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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mTBI, Ocular Motility Disorders, Oculomotor Disorder, Mild Traumatic Brain Injury, Concussion, Mild Concussion, Eye tracking, Questionnaire