Effect of Phases of Menstrual Cycle on Visual Evoked Potential

Objective- Latency and amplitude of P100 of VEP recording is affected by various variables like age, refractive errors, eye dominance, sex hormones etc. so we tried to evaluate the effect of follicular and luteal phase of menstrual cycle on VEP by using LED goggle as stimulation source. Method- We studied 40 healthy female volunteers of age between 17-21yrs with regular menstrual cycle of 282 days in both phases. They were called on 10th day after commencement of menstruation for follicular phase recording and 2-3 days prior to expected date of next menstruation. Result- Normative value for latency of P100 for LED goggle recording is 87.3ms. latency of P100 for right eye was 82.51513.483 ms & 89.26013.414 ms in follicular and luteal phase respectively and p-Value was 0.0221. Latency of P100 for left eye was 85.55314.423 ms & 93.67518.377ms in follicular and luteal phase respectively and statistically significant p-Value of 0.0170. Conclusion - our results suggested that there were significant changes in VEP in during different phases of menstrual cycle thus while recording of VEP in females the phase of menstrual cycle should be kept in mind at the time of interpretation of the result.