Contrast Visual Evoked Potentials under Pattern Stimulus in Ocular Trauma

Abstract

Objective To study the characteristic of contrast visual evoked potentials （CVEP） in patients with ocular trauma. Methods Sixty patients defined as ocular trauma by forensic clinical examination in our center were selected, and split into 0.2-0.3 （Group A）, 0.3-0.5 （Group B） and ≥0.5 （Group C） according to the best corrected visual acuity. The variation characteristics of wave amplitude and latency of CVEP under 100%, 25% and 10% contrast were observed and analyzed statistically. Results （1） Under the same contrast, the wave amplitude of P100 decreased with the decrease of stimulus perspective. （2） Under the same stimulus perspective, the wave amplitude of P100 decreased with the decrease of contrast （P<0.05）. （3） Under the contrast of 100% and 25% with the same stimulus perspective （except 100% 7′ perspective stimulus）, the difference between group A and group B had no statistical significance （P＞0.05）. Between group A and group C, group B and group C, the wave amplitude of P100 gradually increased with the increase of vision （P<0.05）. Under the contrast of 10% with 15′ stimulus perspective, the wave amplitude of P100 increased with the increase of vision （P<0.05）. （4） Under the same contrast with the same stimulation perspective, the latency of P100 wave shortened with the increase of vision, while the difference had no statistical significance （P＞0.05）. Under the same stimulus perspective, the latency of P100 wave was prolonged with the decrease of contrast （P＞0.05）. Conclusion CVEP may become one of the possible methods for the evaluation of contrast visual acuity.

Keywords

• forensic medicine; eye injuries; evoked potentials, visual; visually impaired persons