Variability, repeatability and test-retest reliability of equine flash visual evoked potentials (FVEPs).
Authors: Ström L, Bröjer J, Ekesten B
Journal: BMC veterinary research
Summary
Flash visual evoked potentials (FVEPs) measure electrical brain activity in response to light stimuli and can help diagnose vision problems affecting the optic nerve and central visual pathways in horses, yet their clinical utility has been limited by insufficient data on measurement consistency. Strӧm and colleagues assessed within-subject variability, between-subject variability, and test-retest reliability of FVEPs recorded from neurologically normal adult horses across multiple recording sessions, establishing baseline parameters for what constitutes normal variation versus clinically significant abnormality. Understanding these reliability metrics is crucial for equine practitioners because waveform morphology, peak latencies, and amplitudes can shift with pathology affecting post-retinal structures—but only if practitioners can distinguish genuine pathological changes from normal biological noise. The authors' findings provide the standardised reference values and confidence intervals necessary to interpret FVEPs in clinical cases, improving diagnostic confidence when evaluating horses with suspected vision deficits or neurological disease. For veterinarians, farriers, and rehabilitation specialists managing horses with visual concerns or neurological presentations, this work transforms FVEPs from a research curiosity into a more defensible diagnostic tool with known limitations and reliability thresholds.
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Practical Takeaways
- •FVEPs are now a validated neurological diagnostic tool for horses with suspected post-retinal visual pathway problems; baseline variability data allows practitioners to distinguish normal from pathological responses
- •This standardization enables veterinarians to use FVEP testing clinically to investigate visual dysfunction and central nervous system lesions affecting vision
- •Understanding FVEP reliability supports the development of FVEP testing protocols as part of equine neurological examination in practice
Key Findings
- •Flash visual evoked potentials (FVEPs) can be reliably recorded in normal adult horses and show measurable waveform morphology with specific peak times and amplitudes
- •Within-subject and between-subject variability data were established to enable clinical interpretation of equine FVEP results in pathological cases
- •Test-retest reliability parameters were determined for FVEPs, supporting their use as a diagnostic tool for post-retinal visual pathway disorders in horses