The effect of change of check size and wavelength of stimulus on visual-evoked potential parameters

• Main Author: Mona Abdelkader
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2016-01-01
• Series: Delta Journal of Ophthalmology
• Subjects: amplitude; flash visual-evoked potential; latency; monochromatic flash visual-evoked potential; pattern visual-evoked potential
• Online Access: http://www.djo.eg.net/article.asp?issn=1110-9173;year=2016;volume=17;issue=2;spage=73;epage=79;aulast=Abdelkader
• ISSN: 1110-9173; 2090-4835

Purpose of the study The present study was conducted to evaluate the effect of change of wavelength of flash stimulus and change of check size on the parameters of the visual-evoked potential (VEP) amplitude and latency in normal individuals. Participants and methods The study included 300 eyes of 150 healthy study participants with age range of 20–45 years. They were exposed to a flash visual-evoked potential (FVEP) with white light and blue color, and to a pattern reversal visual-evoked potential with checks subtending visual angles of 15, 30, 60, and 120 min of arc. The measured data were statistically analyzed and summarized by histograms. The interindividual and intraindividual variability in latencies and amplitudes for FVEP were assessed using the coefficient of variation. Results There were statistically significant differences between blue and white FVEP latencies, whereas there were no statistically significant differences between white and blue FVEP amplitudes. Blue FVEP had less interindividual and intraindividual variability. There was a statistically significant difference in latencies between different check sizes. Conclusion Monochromatic FVEP was preferred than white, as there were minimal interindividual and intraindividual variations of latencies and amplitudes. The most preferred check size in pattern VEP was 120′.