‘Gaze shift dynamic visual acuity: A functional test of gaze stability that distinguishes unilateral vestibular hypofunction

2020 ◽  
pp. 1-10
Author(s):  
Po-Yin Chen ◽  
Ying-Chun Jheng ◽  
Shih-En Huang ◽  
Lieber Po-Hung Li ◽  
Shun-Hwa Wei ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Head Rotation ◽  
Measurement Unit ◽  
Healthy Controls ◽  
Dynamic Visual Acuity ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Gaze Stability ◽  
Vestibular Hypofunction ◽  
Field Of Vision

BACKGROUND: Embedded within most rapid head rotations are gaze shifts, which is an initial eye rotation to a target of interest, followed by a head rotation towards the same target. Gaze shifts are used to acquire an image that initially is outside of the participant’s current field of vision. Currently, there are no tools available that evaluate the functional relevance of a gaze shift. OBJECTIVE: The purpose of our study was to measure dynamic visual acuity (DVA) while performing a gaze shift. METHODS: Seventy-one healthy participants (42.79±16.89 years) and 34 participants with unilateral vestibular hypofunction (UVH) (54.59±20.14 years) were tested while wearing an inertial measurement unit (IMU) sensor on the head and walking on a treadmill surrounded by three monitors. We measured visual acuity during three subcomponent tests: standing (static visual acuity), while performing an active head rotation gaze shift, and an active head rotation gaze shift while walking (gsDVAw). RESULTS: While doing gsDVAw, patients with Left UVH (n = 21) had scores worse (p = 0.023) for leftward (0.0446±0.0943 LogMAR) head rotation compared with the healthy controls (–0.0075±0.0410 LogMAR). Similarly, patients with right UVH (N = 13) had worse (p = 0.025) gsDVAw for rightward head motion (0.0307±0.0481 LogMAR) compared with healthy controls (–0.0047±0.0433 LogMAR). As a whole, gsDVAw scores were worse in UVH compared to the healthy controls when we included the ipsilesional head rotation on both sides gsDVAw (0.0061±0.0421 LogMAR healthy vs. 0.03926±0.0822 LogMAR UVH, p = 0.003). Controlling for age had no effect, the gsDVAw scores of the patients were always worse (p <  0.01). CONCLUSION: The gaze shift DVA test can distinguish gaze stability in patients with UVH from healthy controls. This test may be a useful measure of compensation for patients undergoing various therapies for their vestibular hypofunction.

Effect of oculo-motor and gaze stability exercises on postural stability and dynamic visual acuity in healthy young adults

2011 ◽  
Vol 33 (4) ◽  
pp. 600-603 ◽  
Author(s):  
Hiroyuki Morimoto ◽  
Yuji Asai ◽  
Eric G. Johnson ◽  
Everett B. Lohman ◽  
Keiko Khoo ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Young Adults ◽  
Postural Stability ◽  
Dynamic Visual Acuity ◽  
Gaze Stability

Correlation of Head Impact Exposures With Vestibulo-Ocular Assessments

2020 ◽  
Vol 29 (3) ◽  
pp. 310-314 ◽  
Author(s):  
Theresa L. Miyashita ◽  
Paul A. Ullucci
Keyword(s):  
Visual Acuity ◽  
Cumulative Effect ◽  
Head Impact ◽  
Division I ◽  
Dynamic Visual Acuity ◽  
Head Impacts ◽  
Ocular Reflex ◽  
Gaze Stability ◽  
Vestibulo Ocular Reflex ◽  
Subconcussive Impacts

Context: Managing a concussion injury should involve the incorporation of a multifaceted approach, including a vision assessment. The frontoparietal circuits and subcortical nuclei are susceptible to trauma from a concussion injury, leading to dysfunction of the vestibulo-ocular system. Research investigating the effect of cumulative subconcussive impacts on neurological function is still in its infancy, but repetitive head impacts may result in vestibular system dysfunction. This dysfunction could create visual deficits, predisposing the individual to further head trauma. Objective: The purpose of this study was to investigate the cumulative effect of subconcussive impacts on minimum perception time, static visual acuity, gaze stability, and dynamic visual acuity scores. Design: Prospective cohort. Setting: Division I university. Patients: Thirty-three Division I men’s lacrosse players (age = 19.52 [1.20] y). Intervention: Competitive lacrosse season. Main Outcome Measures: At the beginning and end of the season, the players completed a vestibulo-ocular reflex assessment, using the InVision™ system by Neurocom® to assess perception, static acuity, gaze stability, and dynamic visual acuity. Score differentials were correlated with the head impact exposure data collected via instrumented helmets. Results: A significant correlation was found between change in perception scores and total number of head impacts (r = .54), and between changes in dynamic visual acuity loss scores on the rightside and maximum rotational acceleration (r = .36). No statistical differences were found between preseason and postseason vestibulo-ocular reflex variables. Conclusions: Cumulative subconcussive impacts may negatively affect vestibulo-ocular reflex scores, resulting in decreased visual performance. This decrease in vestibulo-ocular function may place the athlete at risk of sustaining additional head impacts or other injuries.

Age-Related Vestibular Dysfunction; Vestibulo-Ocular Reflex, Dynamic Visual Acuity, Dizziness and Falls: A Review

2021 ◽  
pp. 279-292
Keyword(s):  
Visual Acuity ◽  
Balance Control ◽  
Vestibular Dysfunction ◽  
Posture Control ◽  
Complex Nature ◽  
Dynamic Visual Acuity ◽  
Ocular Reflex ◽  
Gaze Stability ◽  
Age Related ◽  
Vestibulo Ocular Reflex

Background: Vestibular and vision functions are important contributors to posture control and fall avoidance. This review examines how the vestibulo-ocular reflex can be rehabilitated to help restore postural control. Methods: PubMed searches (7th April 2021) using the terms ‘vestibulo-ocular reflex’, ‘imbalance and vestibular dysfunction’, ‘vestibular dysfunction and dizziness’, ‘dynamic visual acuity’, ‘vestibular dysfunction rehabilitation’, and ‘gaze stabilization exercises’ yielded 4986, 495, 3576,1830, 3312, and 137 potentially useful publications respectively. Selections of those which were found to be the most relevant and representative of a balanced and current account of these topics, as well as selections from the most relevant reports referenced in those publications, were included in this review. Results: Just as there are age-related losses of static visual acuity even when there are no specific visual pathologies diagnosed, patients may also present with age-related loss of vestibular functions in the absence of specific vestibular pathologies. For example, cases of dizziness which are diagnosed as idiopathic might be usefully classified as age-related as the basis for the initiation of rehabilitation exercises. Conclusions: Apart from age-related loss of vestibular functions, cases diagnosed as having a particular form of vestibular pathology may have that condition exacerbated by age-related losses of vestibular functions. The effects of vestibular rehabilitation gaze stability exercises in patients with vestibular dysfunction are well established and include both improved dynamic acuity and postural stability. Improvements in posture control following rehabilitation of the vestibulo-ocular reflex are apparently due to improved peripheral and/or central vestibular balance control which has occurred in conjunction with enhanced gaze stability. The complex nature of increased fall risk suggests that an interdisciplinary approach to rehabilitation that includes vestibulo-ocular reflex rehabilitation appears likely to be associated with optimum outcomes for both pathological and age-related cases.

scholarly journals Recovery of Dynamic Visual Acuity in Unilateral Vestibular Hypofunction

2003 ◽  
Vol 129 (8) ◽  
pp. 819 ◽  
Author(s):  
Susan J. Herdman ◽  
Michael C. Schubert ◽  
Vallabh E. Das ◽  
Ronald J. Tusa
Keyword(s):  
Visual Acuity ◽  
Dynamic Visual Acuity ◽  
Vestibular Hypofunction

scholarly journals Recovery of Dynamic Visual Acuity in Bilateral Vestibular Hypofunction

2007 ◽  
Vol 133 (4) ◽  
pp. 383 ◽  
Author(s):  
Susan J. Herdman ◽  
Courtney D. Hall ◽  
Michael C. Schubert ◽  
Vallabh E. Das ◽  
Ronald J. Tusa
Keyword(s):  
Visual Acuity ◽  
Dynamic Visual Acuity ◽  
Vestibular Hypofunction ◽  
Bilateral Vestibular Hypofunction

Clinical Evaluation of Dynamic Visual Acuity in Subjects With Unilateral Vestibular Hypofunction

2009 ◽  
Vol 30 (3) ◽  
pp. 368-372 ◽  
Author(s):  
Elizabeth Dannenbaum ◽  
Nicole Paquet ◽  
Gevorg Chilingaryan ◽  
Joyce Fung
Keyword(s):  
Visual Acuity ◽  
Clinical Evaluation ◽  
Dynamic Visual Acuity ◽  
Vestibular Hypofunction

Gaze stability in young adults with previous concussion history

2020 ◽  
Vol 30 (4) ◽  
pp. 259-266
Author(s):  
Linda J. D’Silva ◽  
Catherine F. Siengsukon ◽  
Hannes Devos
Keyword(s):  
Visual Acuity ◽  
Young Adults ◽  
Sleep Quality ◽  
Daytime Sleepiness ◽  
Head Movements ◽  
Control Group ◽  
Dynamic Visual Acuity ◽  
Symptom Scale ◽  
Gaze Stability ◽  
Concussion History

BACKGROUND: Disruption of visual-vestibular interaction after concussion can cause gaze instability with head movements. The long-term impact of concussion on gaze stability is unknown. OBJECTIVE: This cross-sectional comparative pilot study examined gaze stability in the chronic stage after concussion (greater than one year). A secondary objective was to examine the relationship between gaze stability and sleep. METHODS: Outcome measures included: 1. Gaze stability in logMAR (mean loss of dynamic visual acuity (DVA) in the yaw and pitch planes); 2. Pittsburgh Sleep Quality Index (PSQI); 3. Epworth Sleepiness Scale (ESS). Post-Concussion Symptom Scale (PCSS), time since injury, and number of concussions were collected for the people with concussion. RESULTS: The study sample included thirty-four adults (mean age 23.35±1.3 years). Seventeen had a history of 1–9 concussions, with a mean duration of 4.4±1.9 years since last concussion; and 17 were age and sex-matched controls. Mean pitch plane DVA loss was greater in the concussion group compared to the control group (p = 0.04). Participants with previous concussion had lower sleep quality based on the PSQI (p = 0.01) and increased daytime sleepiness based on the ESS (p = 0.01) compared to healthy controls. Mean DVA loss in the pitch plane was significantly correlated with the PSQI (r = 0.43, p = 0.01) and the ESS (r = 0.41, p = 0.02). CONCLUSION: Significant differences in dynamic visual acuity may be found in young adults long after a concussion, compared with those who have no concussion history. Furthermore, loss of dynamic visual acuity was associated with poorer sleep quality and higher daytime sleepiness.

Behavior of the Position Vestibular Pause (PVP) Interneurons of the Vestibuloocular Reflex During Head-Free Gaze Shifts in the Monkey

2005 ◽  
Vol 94 (6) ◽  
pp. 4481-4490 ◽  
Author(s):  
Albert F. Fuchs ◽  
Leo Ling ◽  
James O. Phillips
Keyword(s):  
Head Rotation ◽  
Head Movements ◽  
Type I ◽  
Vestibuloocular Reflex ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Behavioral Studies ◽  
Entire Duration ◽  
Gain Reduction ◽  
The Subject

Most behavioral studies indicate that the efficacy (gain) of the vestibuloocular reflex (VOR) in primates is modulated during the voluntary head movements that accompany large shifts in the direction of gaze. However, the timing and degree of this modulation is the subject of some debate. The neurophysiological substrate for this apparent gain reduction has been sought in the behavior of the type I position vestibular pause (PVP) neuron, a well-known type of interneuron in the direct VOR pathway. With the head fixed, PVPs increase their firing rates with contraversive eye position and with ipsiversive passive head rotation and also cease firing (pause) for the duration of ipsiversive saccades. During head-free ipsiversive gaze shifts, the eyes and head move in the same direction. If the vestibular signal carried by PVPs provides the primary drive for the VOR, the vestibular signal should be present during ipsiversive gaze shifts to the degree that the VOR is present. Of 25 type I PVPs recorded, 21 ceased their discharge for the entire duration of the rapid, eye-saccade component of an ipsiversive gaze shift. The resumption of activity occurred, on average, 13 ms after the end of the saccade. These results suggest that the activity of the vast majority of PVP neurons do not reflect the state of the VOR, but rather PVPs are completely eliminated from participation in the reflex during head-free gaze movements. We conclude that if any modulation of the VOR does exist, it must occur through other, probably longer-latency, pathways.

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