New portable tool to screen vestibular and visual function--National Institutes of Health Toolbox initiative

Abstract

As part of the National Institutes of Health Toolbox initiative, we developed a low-cost, easy-to-administer, and time-efficient test of vestibular and visual function. A computerized test of dynamic visual acuity (cDVA) was used to measure the difference in visual acuity between head still and moving in yaw. Participants included 318 individuals, aged 3 to 85 years (301 without and 17 with vestibular pathology). Adults used Early Treatment of Diabetic Retinopathy Study (ETDRS) optotypes; children used ETDRS, Lea, and HOTV optotypes. Bithermal calorics, rotational chair, and light box testing were used to validate the cDVA. Analysis revealed that the cDVA test is reliable for static (intraclass correlation coefficient [ICC] >/= 0.64) and dynamic (ICC >/= 0.43-0.75) visual acuity. Children younger than 6 years old were more likely to complete cDVA with Lea optotypes, but reliability and correlation with ETDRS was better using HOTV optotypes. The high correlation between static acuity and light box test scores (r = 0.795), significant difference of cDVA scores between those with and without pathology (p </= 0.04), and the good to excellent sensitivity (73%) and specificity (69%) establish that the cDVA is a valid and reliable measure of visual acuity when the head is still and moving, as well as a good proxy of vestibular function to yaw rotation.

Figures

Figure 1

Vision optotypes used included (a) Lea, (b) Early Treatment of Diabetic Retinopathy Study, and (c) HOTV.

Figure 2

Dynamic visual acuity headgear. Rate sensor attached to headband.

Figure 3

Hat incentive for children. To encourage participation and wearing rate sensor, paper hats were attached to headband. Rate sensor was concealed to minimize any anxiety and curiosity.

Figure 4

Comparison of computerized testing of dynamic visual acuity (cDVA) score between those with and without pathology. cDVA score (dynamic visual acuity score – static visual acuity score, in logMAR) differed significantly between those with and without pathology in both younger and older age groups.

Figure 5

Correlation of computerized static visual acuity (SVA) and light box testing scores. SVA scores (in logMAR) attained on computerized test and light box test were highly correlated (r = 0.795; p < 0.001).