Age‐associated changes in the equine flash visual evoked potential

Ström, Lena; Michanek, Måns; Ekesten, Björn

doi:10.1111/vop.12601

Cited by 8 publications

(5 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…9 Another study, however, reported the performance of the flash-VEP in 28 horses under sedation. 22 The decision to use sedative drugs was probably due to the uncooperative nature of this species coupled with the fact that there is no need for fixation for the flash stimulus, unlike the need for fixation when using pattern stimulus.…”

Section: Resultsmentioning

confidence: 99%

Grating Visual Acuity in phakic, aphakic, and pseudophakic Poodles

Safatle

Moraes

Eyherabide

et al. 2020

Veterinary Ophthalmology

View full text Add to dashboard Cite

Objective To compare the grating visual acuity (VA) measured by visual evoked potentials (VEP) in phakic, aphakic, and pseudophakic Poodles. Animals studied Thirty‐six Poodle dogs aged from 4 to 14 years. Procedures Animals were allocated into three different groups according to their lens status: phakic group (n = 12), aphakic group (n = 12), and pseudophakic group (n = 12). Grating VA was measured in cycles/degree (cpd) in all animals using the electrodiagnosis system Roland RETIport® in a dark room without using any mydriatic, sedative, or anesthetic drugs. Results The mean grating VA in the phakic, aphakic, and pseudophakic groups was 5.9 ± 1.0 cpd (20/102—Snellen equivalent), 2.6 ± 0.7 cpd (20/231), and 5.2 ± 1.1 cpd (20/116), respectively. The VA from aphakic eyes was significantly lower when compared to the phakic and pseudophakic eyes (P < .05). There was no significant difference in VA between phakic and pseudophakic eyes. Conclusions The VEP is a useful tool for the evaluation of grating visual acuity in canines. The study showed that IOL implantation following phacoemulsification results in improved VA as measured by VEP compared to that of the aphakic eye and resulted in VA that was similar to that of the normal eye.

show abstract

Section: Resultsmentioning

confidence: 99%

Grating Visual Acuity in phakic, aphakic, and pseudophakic Poodles

Safatle

Moraes

Eyherabide

et al. 2020

Veterinary Ophthalmology

View full text Add to dashboard Cite

show abstract

“…The FVEP waveform recorded in all 17 horses in this study consisted of a series of positive and negative wavelets (P1, N1, P2, N2a, P3, N2, P4 and P5), as previously reported [ 16 , 17 ]. However, some wavelets were only present in a limited number of recordings in all horses.…”

Section: Discussionmentioning

confidence: 99%

“…Seventeen healthy adult Standardbreds (3–19 years old, mean ± standard deviation (SD); 10 ± 5.7 years, 4 geldings, 2 stallions and 11 mares), without any signs of ocular, visual or neurological disease at physical and ophthalmic examination, including obstacle course testing, were included in the study. Horses 1–10 and 1–17 were also included in two previous studies [ 16 , 17 ]. The study was approved by the Regional Ethical Committee (Uppsala Djurförsöksetiska nämnd, Sweden, C254/10 and C39/12).…”

Section: Methodsmentioning

confidence: 99%

“…Light-adapted FVEPs were recorded according to the protocol described by Ström & Ekesten [ 17 ]. All recordings were performed in a clinical examination room at the Horse Clinic at the Swedish University of Agricultural Sciences.…”

Section: Methodsmentioning

confidence: 99%

“…Although FVEPs have been described in normal horses (Fig. 1 ) [ 16 , 17 ], more data on the variability within and between subjects and evaluation of test-retest reliability is required, to adequately interpret results from clinical equine patients. Therefore, the purpose of this study was to describe the variability, repeatability and test-retest reliability of FVEPs recorded from healthy horses.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Variability, repeatability and test-retest reliability of equine flash visual evoked potentials (FVEPs)

2020

Self Cite

View full text Add to dashboard Cite

Background Visual evoked potentials (VEPs) are electrical potentials generated by neurons in the central nervous system in response to visual stimuli. A series of positive and negative wavelets in response to flash-stimuli (flash-VEP; FVEP) or reversing, iso-luminant patterns (pattern-VEP; PVEP) are recorded. Pathological conditions affecting the post-retinal pathways can alter overall waveform morphology, and also affect wavelet peak times and amplitudes. FVEPs have recently been described in horses, but more data on the variability within and between subjects is required, to adequately interpret results from clinical equine patients. Therefore, the purpose of this study was to describe the variability, repeatability and test-retest reliability of equine FVEPs in normal, adult horses. Results Equine FVEPs were recorded from one randomly selected eye in 17 horses, from both eyes in eight of these horses, and also at two separate recording sessions in six horses. N1, P2, N2 and P4 wavelets were present in 100% of the recordings in all horses, while P1, N2a, P3 and P5 were only present in some recordings. Coefficients of variation (CVs) were low for P2, N2 and P4 peak times, but higher for all amplitudes. There were no statistically significant differences comparing peak times and amplitudes between eyes or between sessions. Coefficients of repeatability (CRs) are reported for P2, N2 and P4 peak times between eyes (P2; 5 ms, N2; 18 ms, P4; 18 ms) and also between sessions (P2; 5 ms, N2; 16 ms, P4; 39 ms). Intraclass correlation coefficients (ICCs), as an estimate of test-retest reliability, was assessed to be fair to excellent for most parameters. Conclusions This study provides important data on variability, repeatability and test-retest reliability of FVEPs in normal, adult horses. We conclude that P2, N2 and P4 peak times should be included in the evaluation of equine FVEPs. The large inherent variability of FVEP amplitudes is likely to make them less suitable and useful for establishing a diagnosis on their own in most clinical patients, but they may occasionally provide support to a clinical diagnosis.

show abstract

Ancillary diagnostic aids

2022

Large Animal Neurology

View full text Add to dashboard Cite

Age‐associated changes in the equine flash visual evoked potential

Cited by 8 publications

References 35 publications

Grating Visual Acuity in phakic, aphakic, and pseudophakic Poodles

Grating Visual Acuity in phakic, aphakic, and pseudophakic Poodles

Variability, repeatability and test-retest reliability of equine flash visual evoked potentials (FVEPs)

Ancillary diagnostic aids

Contact Info

Product

Resources

About