Visual evoked potential changes in different phases of menstrual cycle in young females

Background: Visual evoked potential (VEP) is a convenient and non-invasive tool for assessing the functional integrity of visual system. Apart from age and gender visual evoked potential can also be influenced by the varying levels of ovarian hormones in the different phases of menstrual cycle. Aim of the study: To observe the changes of visual evoked potentials in the follicular phase and luteal phase of the menstrual cycle in healthy young women. Materials & Methods: Study group of thirty females between the age group of 18 to 22 years having regular menstrual cycle of 28 days were included in the study. The females with irregular menstrual cycles, Polycystic ovarian diseases( PCOD), refractive error and who were on hormonal pills were excluded from the study. Pattern reversal VEP was recorded by using Neuroperfect EMG 2000 system with installed software during follicular and luteal phases of the same menstrual cycle. Peak P100, N75 and N145 latencies were recorded. Results: Statistical analysis was done by using student ‘t’test. In the present study, mean P100 wave latency (95.55 ±7.11) and mean N145 wave latency(137.98 ±11.44) were reduced in follicular phase, whereas mean P100 wave latency (104.42 ± 5.67) and mean N145 wave latency (146.21 ± 9.01) were increased in luteal phase of menstrual cycle and these changes are statistically significant (pvalue <0.001) . Conclusion: From this study it was found that, In females during follicular phase, PRVEP latencies were shortened and VEP latencies were prolonged during luteal phase of menstrual cycle. So in case of females, before going for any diagnostic conclusion of diseases affecting visual system, the normal variations of PRVEP latencies should be considered.