(PP1506) Feasibility of Dynamic Visual Acuity Test as Virtual Vestibular Screener

Introduction: Telehealth has shown promise as a viable alternative modality for providing healthcare when there are limitations placed on traditional in-person care, and its importance has been highlighted throughout the COVID-19 pandemic. (e.g. Speyer et al., 2017). Continued effort is needed to provide robust evidence to support the efficacy of remote vestibular assessment.

A complete vestibular examination requires specialized equipment, and requires patients to travel to a clinic for time-intensive testing. A remote screening to identify patients who need a full diagnostic evaluation will be helpful in reducing the burden for both the clinic and patients. Dynamic Visual Acuity test (DVA) is a useful screening tool. The purpose of this study is to assess sensitivity and specificity DVA adapted for remote administration. The results of this study will provide evidence for the feasibility of telehealth for vestibular screening. 

Methods: Participants are recruited from Gallaudet University and surrounding DC area. Both typically hearing and deaf individuals are recruited to increase the chances of recruiting volunteers who have vestibular impairments. Exclusion criteria are neurological condition/s, recent head injury, or trauma that impacts cognitive functioning.  

DVA is completed in both yaw and pitch planes using a Tumbling E Eye Chart rather than the Snellen, to accommodate participants who are unfamiliar with the English alphabet and those who use other language modalities. The virtual DVA is administered via Zoom, with tumbling Es projected using PowerPoint slides. Each slide displays one line (font size) of the chart; four slides of varied direction of the tumbling E’s are prepared. The font and size of each line are standardized based on the traditional chart. Participants sit at eye level with their computer, using glasses/contact lenses as needed. The participants sit at an appropriate distance from their screen and read the smallest line they can, which will be considered their baseline. Dynamic visual acuity is tested while the participant oscillates their head in the yaw and pitch plane at approximately 2 Hz. The shift in the smallest line they can read is recorded for each plane. If the participant is unable to continue oscillating their head while reading, the run is excluded. 

The in-person DVA testing is conducted with the participant standing 10 feet from the eye chart posted eye-level. Once the static visual acuity is obtained, the researcher will oscillate the participant’s head at approximately 2 Hz and note the shift in the smallest line they are able to read. 

vHIT is performed with Interacoustics EyeSeeCam. The participant sits in a chair, while the researcher performs impulses in the lateral, RALP, and LARP planes, at a peak velocity of 150°/s or greater. Both cVEMP and oVEMP is obtained using 500-Hz STB, from the ipsilateral sternocleidomastoid muscle and contralateral inferior oblique muscle to the stimulated ear, respectively. A standard VEMP method is used. 

Sensitivity and specificity of DVA will be determined.

Results: Data collection is ongoing and on track to be completed by February. We have funding to complete testing on 50 participants.