Application of the Virtual Reality-Pattern Visual Evoked Potential in Forensic Visual Acuity Evaluation / 法医学杂志

Objective To explore a kind of visual evoked potential test equipment and method that is more suitable for the application of forensic clinical visual acuity evaluation. Methods Thirty-four volunteers （68 eyes） were selected, including 15 males and 19 females, aged between 20 and 40 years. Test lenses were placed before the tested eyes of volunteers to induce refractive myopia with insert method, and the diopter lenses were adjusted so that the visual acuity level of one eye of volunteers was above 0.8, and the visual acuity of the other eye was at moderate damage level （<0.3 and ≥0.1）. The tests were carried out under the binocular simultaneous asynchronous stimulation mode （hereinafter referred to as "binocular mode"） and monocular separate stimulation mode （hereinafter referred to as "monocular mode"） of virtual reality-pattern visual evoked potential （VR-PVEP）, and the amplitude of PVEP of volunteers under the two modes was compared at four spatial frequencies of 8×8, 16×16, 24×24 and 32×32. Results The differences in the amplitude of P100 wave between monocular and binocular modes at 8×8 spatial frequency had no statistical significance and the differences in amplitude of P100 wave between monocular and binocular modes at 16×16, 24×24, and 32×32 spatial frequencies had statistical significance （P<0.05）. The amplitude of the same eye in monocular mode was higher than that in binocular mode. Through correlation analysis, it was found that the amplitude of P100 wave in monocular mode was moderately correlated with amplitude of P100 wave in binocular mode. Conclusion In forensic identification practice, VR-PVEP is helpful for overcoming the disturbance of poor fixation, and to increase the reliability of PVEP evaluation results. It can greatly shorten the detection time of PVEP and improve work efficiency.

Application of PRVEP Waveform Amplitude Ratio to Evaluate Visual Acuity and Its Forensic Significance / 法医学杂志

Objective To research the correlation between the visual acuity ratio and pattern reversal visual evoked potential （PRVEP） P100 waveform amplitude ratio of both eyes. Methods Forty-seven volunteers were selected, and the visual chart visual acuity of both eyes was measured. The visual acuity ratio of the eye with poor vision to the eye with better vision was calculated by five grade notation method. The amplitudes of P100 waveforms of both eyes were recorded respectively by using black-and-white checkerboard PRVEP and chosing 1°, 15' stimulating visual angle, and the ratio of amplitudes between the two eyes was also calculated. SPSS 20.0 software was used to analyze the correlation between the visual acuity ratio and the ratio of P100 waveform amplitudes between the two eyes. Return test and linear regression analysis with the binocular ratio of P100 waveform amplitudes as the independent variable （x） and the binocular visual acuity ratio as the dependent variable （y） were made. Results There was a positive correlation between the binocular visual acuity ratio and the ratio of P100 waveform amplitudes under 15' stimulating visual angle （Pearson correlation coefficient was 0.62, P=0.000）. The fitting linear regression equation was y=0.090 x+0.846 （F=20.954, P=0.000）. There was no significant correlation between the binocular ratio of visual acuity and the binocular ratio of P100 waveform amplitudes under 1° stimulating visual angle （P>0.05）. Results of return test showed that there was no statistical significance in the difference between visual acuity estimated by equation and actual detected visual acuity. Conclusion In forensic appraisal of monocular injury, fitting linear regression equation of binocular visual acuity ratio and the binocular ratio of P100 waveform amplitudes under 15' stimulating visual angle, is helpful for visual acuity level estimation of the injured eye to some extent.

Assessment of the Original Height of L1~2 after Vertebral Compression Fracture / 法医学杂志

OBJECTIVES@#To explore the assessment method of original height of L1-2 after vertebral compression fracture and its application value in forensic clinical practice.@*METHODS@#A total of 154 normal thoracic and lumbar X-ray films were collected, and 140 cases were used as experimental group while 14 cases as validation group. The heights of anterior （Ha） and posterior （Hp） vertebral body of T₁₂-L₃ vertebrae in each X-ray image were measured. In the experimental group, the correlation analysis between HaL₁ and HaT₁₂, HpT₁₂, HpL₁, HaL₂ and HpL₂ was carried out, and regression equation was established via fitting. The correlation analysis between HaL₂ and HaL₁, HpL₁, HpL₂, HaL₃, HpL₃ was performed, and the regression equation was also established via fitting. The difference between the predicted and measured values of HaL₁ and HaL₂ in validation group was compared.@*RESULTS@#In the 140 normal subjects, HaL₁ （y₁） was well correlated with HaT₁₂ （x₁） and HaL₂（x₂）, and the multiple linear regression equation was y₁=2.545+0.423 x₁+0.486 x₂ （determining coefficient R²=0.712, P<0.05; F=169.206, P<0.05）. There was no significant difference between the predicted and actual measured values of HaL₁ in the validation group （ P>0.05）. HaL₂ （y₂） was well correlated with HaL₁ （x₃） and HaL₃ （x₄）, and the multiple linear regression equation was y₂=4.354+0.530 x₃+0.349 x₄ （determining coefficient R²=0.689, P<0.05; F=151.575, P<0.05）. There was no significant difference between the predicted and actual measured values of HaL₂ in the validation group （ P>0.05）.@*CONCLUSIONS@#It is more appropriate to evaluate the original height of L₁ or L₂ single vertebrae by comparing with the height of the anterior edge of the upper and lower adjacent vertebral bodies.

Contrast Visual Evoked Potentials under Pattern Stimulus in Ocular Trauma / 法医学杂志

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.

Comparison of anterior chamber angle examination by UBM, SL-OCT and gonioscopy / 法医学杂志

OBJECTIVE@#To compare the agreement of anterior chamber angle examination by ultrasound biomicroscope (UBM), slit lamp optical coherence tomography (SL-OCT), and gonioscopy in angle recession and angle closure.@*METHODS@#The anterior chamber angle was measured with UBM, SL-OCT and gonioscopy in turns for temporal, nasal, superior and inferior quadrant in the same dark room. The results were compared with the agreement of the three methods in angle recession and angle closure by χ2 test and Kappa test.@*RESULTS@#There were no statistically significant differences of the three methods in testing angle closure and angle recession (P>0.05). The consistency of UBM and gonioscopy was better (Kappa value of 0.882) than that of SL-OCT and gonioscopy (Kappa value of 0.624).@*CONCLUSION@#When testing angle recession, UBM is better than SL-OCT with gonioscopy as the standard. When testing angle closure, UBM, SL-OCT and gonioscopy have good agreement.

Clinical observation on combination of compound xuanju capsule and clomiphene citrate in treating ovulatory dysfunctional infertility patients of Shen-yang deficiency / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the therapeutic efficacy of combination of Compound Xuanju Capsule (CXC) and clomiphene citrate (CC) for ovulatory dysfunctional infertility (001) patients of Shen-yang deficiency syndrome (SYDS).</p><p><b>METHODS</b>Totally 87 001 patients of SYDS were randomly assigned to 2 groups, the treatment group (44 cases, treated with CXC and CC) and the control group (43 cases, treated with CC alone). The post-treatment clinical symptoms, the cervical mucus, the endometrial thickness, the quality of follicles, the ovulation, and the pregnancy rate, and so on were observed.</p><p><b>RESULTS</b>In aspect of improving the patients' SYDS, the effective rate was 86.4% (38/44) in the treatment group and 25.6% (11/43) in the control group. It was better in the treatment group (P < 0.01). After treatment better effects on the cervical mucus, the endometrial thickness, and the pregnancy rate were obtained in the treatment group, showing statistical difference when compared with the control group (P < 0.05). There was no statistical difference in the rate of ovulation and mature follicular numbers between the two groups (P > 0.05).</p><p><b>CONCLUSION</b>CXC combined CC could ameliorate hypoestrinemia-like effects on the endometrium, increase the endometrial thickness, and be favorable to the pregnancy in treating ODI patients of SYDS.</p>