Flash Visual Evoked Potential as a Suitable Technique to Evaluate the Extent of Injury to Visual Pathway Following Head Trauma

Author(s): Fatemeh Sarzaeim, Mahboubeh Hashemzehi, Seyed Mohammad Masoud Shushtarian, Ahmad Shojaei, Jalil Naghib

Aim: A head injury is any trauma to the scalp, skull or brain. This may cause vision problems, such as blurred or double vision and difficulty with eye movements focus and finally total blindness. Visual evoked potential is an electrophysiological technique to survey the visual pathway. The aim of present work is to look for visual pathway disturbances in patients with visual dysfunction due to head trauma. Patients and Methods: Twenty eyes with different stages of visual fall due to head accident were taken for the purpose of present research work. The patients were all male with age range of 18 to 30 years. The latency and amplitude of visual evoked potential P100 peak was recorded for these patients and 16 age and sex matched control with healthy visual system mainly visual pathway. Results: The mean age was 24.45±4.86 and 24.7±4.21 in case and control groups respectively. Both case and control groups were male and therefore the difference in values were not statistically significant as far as age (P =0.698) and sex were concerned. The visual acuity in case and control were 0 ± 0 and 1.42 ± 0.94 respectively which was statistically significant in two groups (P <0.001). The values for mean latency were 130.3 ± 7.16 and 99 ± 2.93 for case and control groups respectively. In case of mean amplitude, the values were 1.5 ± 0.6 and 7.6 ± 1.9 in case and control groups respectively. The values for visual evoked potential were statistically significant for latency (P <0.001) and amplitude (P <0.001) in between case and control groups. Conclusion: Head trauma might produce visual dysfunction mostly visual pathway which can be diagnosed by latency and amplitude of visual evoked potential P100 peak.