Execution
- 1Measure static visual acuity first using a standardized eye chart or computerized display.
- 2Ask the patient to read optotypes while the head is passively or actively moved horizontally or vertically at a controlled speed.
- 3Keep head movement amplitude and speed consistent across trials.
- 4Record the number of lines lost compared with static visual acuity.
- 5Compare performance with age-appropriate norms and symptom response.
Positive outcome
A loss of more than about two to three lines compared with static acuity is commonly considered abnormal and suggests impaired gaze stability. Oscillopsia or symptom provocation during head movement supports vestibular involvement. Poor vision, cervical pain, attention, and inconsistent head speed can create false positives.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Herdman et al. (1998) | computerized DVA assessment study | NA | NA | NA | NA |
| Schubert et al. (2002) | vertical DVA study | NA | NA | NA | NA |
CommentDVA is a functional gaze-stability measure rather than a complete vestibular diagnosis. It is useful for quantifying impairment and reassessing vestibular rehabilitation response. Standardization matters because head speed and visual display method strongly affect results.
Low Clinical Value