Objectives: 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).
Conclusions: CVEP may become one of the possible methods for the evaluation of contrast visual acuity.
Keywords: evoked potentials, visual; eye injuries; forensic medicine; visually impaired persons.
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