Validation of Clinical Outcome Measures Specific to mTBI-Related Oculomotor Disorders

Number of participants with abnormal near point of convergence

The ability to converge the eyes. A near point rod will be used with a 20/30 column of letters. The target will be moved towards the participant slowly, and when diplopia occurs, this will be recorded as the NPC break. The target will then be moved away from the eyes until single vision is regained, and this will be recorded as the NPC recovery. The unit of measure is cm and the NPC will be measured 3 times, with 10 seconds in between each measure, and averaged for each participant.

Number of participants with abnormal positive fusional vergence

Compensatory ability to overcome exophoria. A handheld prism bar will be used along with a vertical column of 20/30 letters. The prism will be placed before one eye, and the participant will be asked to maintain clear, single vision. Participants will then report when the target becomes blurred (blur), then double (diplopia), and finally return to single vision (recovery). The unit of measure is prism diopters, and it will be measured three times, with 10 seconds in between each measurement, and averaged for each participant.

Number of participants with abnormal vergence facility

This is a measure of vergence velocity. Using a 12-base-out and 3-base-in prism, participants will be instructed to regain clear single vision as quickly as possible. The investigator will count the number of times this can be accomplished in one minut.e

Number of participants with abnormal accommodative amplitude

A near point rod will be used along with a column of 20/30 letters. The test will be performed monocularly, first with the left eye covered, and then with the right eye covered. The target will slowly be moved towards the participant, and the participant will be instructed to report when the target becomes blurred. The amplitude of accommodation will be measured 3 times, with 10 seconds in between each measure

Number of participants with abnormal accommodative facility

This test assesses the speed and endurance of accommodation. A column of 20/30 letter will be used along with a timer, and +2.00D and -2.00D lens flippers. The test will be performed monocularly. The +2.00D lens will be placed before the participant's eye, and the participant will be asked to clear the target as quickly as possible. Once the participant clears the target, the -2.00D lens will be placed before the eye, and the participant will be asked to report when the target becomes clear again. This will be repeated as many times as possible within one minute. The investigator will report how many times this occurs in one minute.