An Essential Exercise for Head Motion Induced Oscillopsia

Impaired visual acuity during head movement is a common issue following vestibular loss, particularly complete bilateral vestibular loss.1 The impairment results from deficiency in the vestibular ocular reflex (VOR), which stabilizes gaze during dynamic activities that involve head displacement.

Gaze stabilization is important to optimize visual acuity with driving, shopping, walking, and athletic activities. Embedded (“covert”) saccades during head movements are the primary compensation mechanism for a defective vestibular ocular reflex.2

Two-Target VOR Exercise

To improve gaze stabilization, we can use the Two-Target VOR exercise:3,4

  1. Use two printed targets that are legible when the head is stationary.
  2. Instruct the patient to hold the targets approximately 12 inches apart and at arm’s length.
  3. Cue the patient to move their eyes and head to a target.
  4. Instruct the patient to shift their gaze to the other target followed by a rapid head movement in the same direction.
  5. Repeat step 4 in the opposite direction.

The goal of this exercise is to maintain legibility of the printed target during the head movement. Variations and progressions of the exercise include:

  • Placing the targets in a variety of planes
  • Varying eye to target distances
  • Increasing head movement velocity
  • Adding linear head movements
  • Varying the direction of the head rotation to include vertical and oblique head movement

Additional gaze stabilization exercises for head motion induced oscillopsia include VOR x1, VOR x2, Imaginary Targets, and Translation VOR.

References
  1. Herdman SJ, Tusa RJ, Blatt P, Suzuki A, Venuto PJ, Roberts D.  Computerizeddynamic visual acuity test in the assessment of vestibular deficits. Am J Otol. 1998 Nov;19(6):790-6.
  2. Mantokoudis G, Schubert MC, Tehrani AS, Wong AL, Agrawal Y. Early adaptation and compensation of clinical vestibular responses after unilateral vestibular deafferentation surgery. Otol Neurotol. 2014 Jan;35(1):148-54.
  3. Herdman SJ, Hall CD, Schubert MC, Das VE, Tusa RJ. Recovery of dynamic visual acuity in bilateral vestibular hypofunction. Arch Otolaryngol Head Neck Surg. 2007 Apr;133(4):383-9.
  4. Herdman SJ, Schubert MC, Das VE, Tusa RJ. Recovery of dynamic visual acuity in unilateral vestibular hypofunction. Arch Otolaryngol Head Neck Surg. 2003 Aug;129(8):819-24.