Visual Behaviours (ViBes) in Cerebral Visual Impairment: Validating a Descriptive Tool to Support Diagnosis and...

Area of Science:

• Ophthalmology
• Developmental Pediatrics
• Neuroscience

Background:

• Cerebral visual impairment (CVI) is a leading cause of vision loss in children.
• Current diagnostic methods for CVI, relying on visual behaviors (ViBes), are challenging for pre-verbal and pre-motor children.
• A structured approach is needed to record visual behaviors in children with complex needs to facilitate CVI diagnosis.

Purpose of the Study:

• To develop a matrix of visual behaviors for pre-verbal and pre-motor children with visual impairment.
• To establish the content validity and inter-rater reliability of this new matrix, termed the ViBe matrix.
• To address the diagnostic barrier faced by children with complex needs who cannot undergo standard visual assessments.

Main Methods:

• Visual behavior descriptors were collated and categorized by vision professional consensus.
• A matrix was created with three functions (attention, field/fixation, motor response) and five levels (0-4).
• 17 video clips of children exhibiting CVI-related visual behaviors were independently scored by six vision professionals using the ViBe matrix to assess inter-rater reliability.

Main Results:

• The ViBe matrix was developed, categorizing visual behaviors into specific functions and levels.
• Inter-rater reliability was assessed using Cohen's kappa, yielding a score of 0.67.
• This score indicates moderate-to-strong agreement among the raters using the ViBe matrix.

Conclusions:

• Standardized descriptors, like those in the ViBe matrix, can assist clinicians and teachers in identifying visual concerns in children with complex needs.
• The ViBe matrix demonstrates acceptable inter-rater reliability, making it a potentially valuable tool for research and clinical practice.
• This matrix can aid in the identification and diagnosis of CVI in populations unable to access conventional testing methods.