Age-associated changes in the equine flash visual evoked potential.
Abstract: To investigate age-associated changes of flash visual evoked potentials (FVEPs) in sedated horses. Methods: Twenty-eight clinically healthy Standardbred Warmblooded trotters, aged 36 hours to 28 years. Methods: Light-adapted FVEPs and FERGs were recorded (An-vision RETIport, Roland-consult, Germany) in response to flash stimuli. Sedation was obtained using alpha-2-agonists intravenously. Akinesia of the eyelids was induced and pupils were dilated. Results: Reproducible FVEPs and FERGs were readily recorded from all foals and horses. The FVEP waveform included up to four positive components (P1-P5) and two negative components (N1 and N2) and FVEP waveform morphology was similar across all age groups. Some differences in peak times and amplitudes associated with increasing age were observed. FVEP amplitudes recorded from newborn foals were well above the amplitudes observed in normal adult horses and FVEP peak times were somewhat shorter. In adult horses, a significant increase in P4 peak time and a gradual decrease in amplitudes, mainly for N2P4, were seen across the life-span. Conclusions: The overall equine FVEP waveform was similar across the normal life-span of the horse in our cross-sectional study. We found that the visual system of the foal seems to be well developed already at birth. Furthermore, our results showed a decrease in amplitudes and increase in some peak times with increasing age. We recommend that age-matched controls should be used when evaluating foals and young horses in clinical practice, whereas horses over the age of three years can be compared to other adult horses.
© 2018 American College of Veterinary Ophthalmologists.
Publication Date: 2018-09-13 PubMed ID: 30211481DOI: 10.1111/vop.12601Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research article presents a study investigating how a horse’s vision changes with age, focusing on variability in flash visual evoked potentials (FVEPs). The results showed that while the visual system of foals is well developed at birth, changes in peak times and amplitudes related to ageing do occur, with a decrease in amplitudes and an increase in some peak times.
Methods
- The study used a population of 28 clinically healthy Standardbred Warmblooded trotters, ranging in age from 36 hours to 28 years.
- The horses’ flash visual evoked potentials (FVEPs) and Flash Electroretinograms (FERGs) were measured. These physiological measures are useful in understanding visual functioning and potential defects.
- The equine subjects were sedated using intravenous alpha-2-agonists to ensure they remained still during the procedure.
- To further facilitate the recording process, akinesia (muscular paralysis) of the eyelids was induced, and the pupils were dilated.
Results
- Reproducible FVEPs and FERGs were recorded from all foals and horses from the various age groups.
- The FVEP waveform had up to four positive and two negative components, and its overall shape and characteristics were consistent across all age groups.
- However, some differences in peak times and amplitudes were observed with increasing age, suggesting there are changes in the visual system as horses age.
- It was observed that FVEP amplitudes recorded from newborn foals were much larger than amplitudes observed in adult horses. Additionally, FVEP peak times were somewhat shorter in newborn foals.
- For adult horses, an increase in peak time for P4 and a gradual decrease in amplitudes, mainly for N2P4, were observed over the horses’ lifespan.
Conclusion
- In conclusion, the overall characteristics of the equine FVEP waveform are consistent across the normal lifespan of the horse.
- However, the findings demonstrate that the visual capabilities of a newborn foal are well developed, and there are changes in the visual system as the horse ages – observable in changes in FVEP peak times and amplitudes.
- The authors recommend the use of age-matched controls when evaluating the vision of foals and young horses in clinical practice due to these temporal and amplitude changes.
- For horses above three years of age, comparisons can be readily made with other adult horses.
Cite This Article
APA
Ström L, Michanek M, Ekesten B.
(2018).
Age-associated changes in the equine flash visual evoked potential.
Vet Ophthalmol, 22(4), 388-397.
https://doi.org/10.1111/vop.12601 Publication
Researcher Affiliations
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
- Referral Animal Hospital Strömsholm, Strömsholm, Sweden.
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
MeSH Terms
- Aging / physiology
- Animals
- Animals, Newborn
- Evoked Potentials, Visual
- Female
- Horses / physiology
- Male
Citations
This article has been cited 1 times.- Ström L, Bröjer J, Ekesten B. Variability, repeatability and test-retest reliability of equine flash visual evoked potentials (FVEPs). BMC Vet Res 2020 Jul 29;16(1):261.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
