Kennis

Abstract

Background
The aim of this Delphi study was to reach consensus about defnition, operationalization and assessment of visual pursuit (VP) and visual fxation (VF).

Methods
In a three-round international Delphi study, clinical and research experts on disorders of consciousness indicated their level of agreement on 87 statements using a 5-point Likert scale. Consensus for agreement was defned by a median of 5, an interquartile range (IQR)≤1, and≥80% indicating moderate or strong agreement.

Results
Forty-three experts from three continents participated, 32 completed all three rounds. For VP, the consensus statements with the highest levels of agreement were on the term ‘pursuit of a visual stimulus’, the description ‘ability to follow visually in horizontal and/or vertical plane’, a duration>2 s, tracking in horizontal and vertical planes, and a frequency of more than 2 times per assessment. For VF, consensus statements with the highest levels of agreement were on the term
‘sustained VF’, the description ‘sustained fxation in response to a salient stimulus’, a duration of>2 s and a frequency of 2 or more times per assessment. The assessment factors with the highest levels of agreement were personalized stimuli, the use of eye tracking technology, a patient dependent time of assessment, sufcient environmental light, upright posture, and the necessity to exclude ocular/oculomotor problems.

Conclusion
This frst international Delphi study on VP and VF in patients with disorders of consciousness provides provisional operational defnitions and an overview of the most relevant assessment factors.

Keywords
Visual pursuit, Visual fxation, Disorders of consciousness, Delphi study