For professionals

Abstract

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

Methods
In a three-round international Delphi study, clinical and research experts in the field of disorders of consciousness indicated that they agreed on 87 statements using a 5-point Likert scale. Consensus for agreement was defined 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 degree of agreement were related to the term 'the pursuit of a visual stimulus', the description 'the ability to visually track in horizontal and/or vertical planes', 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 degree of agreement on the deadline
'persistent VF', the description 'persistent fxation in response to a conspicuous stimulus', a duration of >2 s and a frequency of 2 or more times per assessment. The assessment factors with the highest degree of agreement were personalized stimuli, the use of eye-tracking technology, a patient-dependent time of assessment, adequate ambient light, upright posture, and the need to rule out ocular/oculomotor problems.

Conclusion
This first international Delphi study of VP and VF in patients with disorders of consciousness provides preliminary operational definitions and an overview of the most relevant assessment factors.

Keywords
Visual Chase, Visual Fxation, Disorders of Consciousness, Delphi Study