Abstract
AbstractPurpose Comparison between the results of FVEP examinations conducted with various stimulators (Ganzfeld, Mini Ganzfeld i Flash Goggles) as well as for opened and closed eyes.Methods 17 volunteers (34 eyes), including 11 females, aged 23‐56 (average age: 30 years) have been examined with Roland Consult electrophysiological equipment. Basing on Wilcoxon signed‐rank test the amplitude and the latency of P2 wave have been compared: 1. of results acquired with each of three stimulators; 2. of results acquired with eyes opened and eyes closed.Results Mean P2 amplitude (latency) acquired with Ganzfeld stimulation amounted to 12 µV (130 ms), acquired with Mini Ganzfeld stimulation amounted to 7 µV (124 ms) and acquired with Flash Goggles amounted to 9 µV (113 ms). The results statistically significantly differed (p < 0,0001) between all compared stimulators. Mean P2 amplitude (latency) acquired with Ganzfeld stimulation amounted to 12 µV (130 ms), acquired with Mini Ganzfeld stimulation amounted to 7 µV (124 ms) and acquired with Flash Goggles amounted to 9 µV (113 ms) with eyes opened and accordingly 11 µV (131 ms), 9 µV (126 ms) and 6 µV (120 ms) with eyes closed. The results for eyes opened and eyes closed statistically significantly differed (p < 0,001) for Mini Ganzfeld as well as for Flash Goggles stimulators.Conclusion The amplitude and latency of P2 FVEP acquired with different stimulators cannot be compared. Keeping eyes closed does not significantly alter the amplitude and latency of P2 FVEP only in case of Ganzfeld stimulation. The results acquired with other stimulators can be faulty if the patient closed eyes during examination.
Highlights
Flash visual evoked potentials (FVEP) have been used in ophthalmology and neurology since 1960s
The mean P2 amplitude acquired with the Ganzfeld bowl stimulation with open eyes amounted to 13 lV (129 ms), that acquired with the Mini Ganzfeld stimulation to 7 lV (114 ms), and that acquired with the Flash Goggles to 10 lV (110 ms) (Tables 1, 2; Figs. 1, 2)
The mean P2 amplitude acquired with the Ganzfeld bowl stimulation with eyes closed amounted to 11 lV (127 ms), that acquired with the Mini Ganzfeld stimulation to 8 lV (125 ms), and that acquired with the Flash Goggles to 8 lV (121 ms) (Tables 3, 4)
Summary
Flash visual evoked potentials (FVEP) have been used in ophthalmology and neurology since 1960s. The flash stimulus may not be considered to be the first choice in obtaining VEP, since pattern visual evoked potentials (PVEP) are much more reproducible and consistent among patients. PVEP require stable fixation, good cooperation and correction of refractive errors. This type of stimulation is sometimes difficult to perform in babies and young children, especially in the presence of a developmental disability or severe vision impairment. In the presence of developmental disability compliance and understanding are limited and standard vision assessment techniques are not possible regardless of age. For many patients flash stimulation may be the optimum tool for visual evoked potential assessment
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
