Dynamic Visual Acuity Test - Instrumented

Bilateral Vestibular Hypofunction and TBI, in healthy adult controls and pediatric patients (Rine et al 2012; n= 318: n = 301 healthy controls, n = 17; mean age age range 3-85) using HOTV, EDTRS, and Lea Optotypes. 

• Adequate to Good test-retest reliability for active yaw head movements: varies by age and optotypes selection 
• ICC = 0.55 for HOTV
• ICC = 0.65 for ETDRS 
• ICC = 0.43 for Lea

Patients with vestibular deficits (UVH and BVH) and non-vestibular dizziness (Schubert et al 2002; N = 13 UVH; mean age= 54.6 (15.2) years; N = 11 BVH; mean age= 61.0 (11.9) years; N = 10 dizziness mean age 54.9 (20.4) years) 

• Excellent test-retest reliability for active pitch head movements, ICC: r = 0.94 (dizzy patients)
• Excellent test – retest reliability for active pitch head movements, ICC: r = 0.89 (healthy control patients)

Unilateral and Bilateral Vestibular Hypofunction (UVH and BVH)(Herdman, 1998; N = 11; mean age = 68.7 (11.6) years) 

• Excellent test-retest reliability for active yaw impulses, ICC: r = 0.83

Predictive Validity: Yaw, Active

Unilateral and Bilateral Vestibular Hypofunction (Herdman et al 1998)

• Excellent Sensitivity (94.5%) for identifying vestibular hypofunction in patients vs. healthy controls.
• Excellent Specificity (95.2%) for identifying vestibular hypofunction in patients vs. healthy controls. 
• Excellent Positive Predictive Value (96.3%) 
• Excellent Negative Predictive Value (93%) 

Predictive Validity: Yaw Active and Passive 

Unilateral and Bilateral Vestibular Hypofunction (Vital 2010; n= 100 healthy control participants; mean age = 45 (16) years) without otological and neurological disorders; n = 15 patients (mean age, 54 (13) years with unilateral or bilateral peripheral vestibular loss). Study investigators assessed participants at rotational velocities of 100 d/s and 150 d/s using active and passive yaw DVA and scleral search coil. 

• High Sensitivity (100%) for identifying unilateral or bilateral vestibular hypofunction in patients vs. healthy controls.

• High Specificity (94%) for identifying unilateral or bilateral vestibular hypofunction in patients vs. healthy controls.

• Passive impulses (z = 2.27) and faster rotational head movement testing velocity (at 150 d/s) (z = 2.08) significantly improved discrimination between control and patient participants; Best between groups discrimination occurred for rapid head movements under passive conditions (z = 2.72). 

Bilateral Vestibular Hypofunction and TBI, in healthy controls and pediatric patients (Rine et al 2012; n= 318: n = 301 healthy controls, n = 17; age range 3-85) using ETDRS optotype model. 

• Good Sensitivity = 73%
• Good Specificity = 69%.

Predictive Validity: Active Pitch 

Unilateral and Bilateral Vestibular Hypofunction (Schubert 2002)

• Poor Sensitivity (23%) patients with UVH
• Adequate Sensitivity (54.5%) patients with BVH
• Excellent Specificity (90%) patients with UVH and BVH

Concurrent Validity 

DVA and GST in older adults (Ward et al 2010; n = 40 (n =20 older adults mean age = 76.3 (5.3) years, n= 20 young controls mean age = 25.2 (3.2)

•  Good (Spearman’s r = -0.62) Active Yaw

• Fair (Spearman’s r = -0.38) Active Pitch 

DVA and Scleral Search Coil in healthy controls and patients with unilateral and bilateral vestibular loss (Vital 2010)

• Excellent (r ² = 0.72, p < 0.001)  Correlation of DVA loss and VOR gain (1 – gaze V/ head V) ) measured during quantitative passive head impulse testing (HIT)

vDVA and rotary chair in patients with vestibular deficits (UVH and BVH) and non-vestibular dizziness (Schubert et al 2002)

Distribution of patient subjects by positive and negative vertical dynamic visual acuity (vDVA) scores.

Key: UVH- Unilateral Vestibular Hypofunction, BVH- Bilateral Vestibular Hypofunction, DZ- dizziness

Positive DX, positive diagnosis (positive caloric and rotary chair test result); 

Negative DX, negative diagnosis (negative caloric and rotary chair test result); 

Abnormal vDVA, vertical dynamic visual acuity Log-MAR score > 2 SD above the mean for age-matched normal subjects;

Normal vDVA, vDVA (LogMAR) score within 2 SD of the mean for age-matched normal subjects; DZ, nonvestibular dizziness; UVH, unilateral vestibular hypofunction; BVH, bilateral vestibular hypofunction.

Passive, Yaw plane impulses can localize side of vestibular lesion as established by Caloric Assessment

Vestibular Disease (UVL, BVL) (Herdman 2001)

• Unpredictable timing and direction head movements result in significantly degraded DVA relative to predictable (active) head movements toward the affected side with UVL (p < 0.001) and BVL (0.004).
• Unpredictable head movements have a greater effect on DVA in older subjects than younger in patients with vestibular loss (p < 0.001) (Herdman 2001; Healthy n = 26; mean age = 39.6 (15.5) years; UVL n = 20; mean age = 66.7 (13.1) years; BVL n = 7; mean age = 63.4 (12.7) years).

Superior Canal plugging post dehiscence (Schubert 2006)

• Passive, head thrust DVA in individual canal planes (Right Anterior, Left Posterior, Left Anterior, or Right Posterior) accurately quantifies gaze instability in patients with singular canal plane deficits.   (Schubert 2006; n = 19 healthy controls mean age = 34.4 (11.8) years, n = 5 pre SSCC plugging and 6 SSCC plugging mean age = 47 (9.1) years. 

DVA while walking in normal and patients with BVH (Hillman 1998; n = 10 healthy controls mean age = 30.8; n = 5 with BVH, mean age = 40). 

• Gaze stability during treadmill locomotion in patients with BVH was significantly degraded relative to DVA in healthy control participants.

Healthy Adult Controls

(Herdman, 1998; n = 27; mean age= 39.3 (13.7) years). Active Yaw Head movement

Healthy Adult Controls 

(Herdman, 1998; n = 27; mean age= 39.3 (13.7) years) 

Excellent test retest reliability active yaw impulses, ICC: r = 0.87