Value of ocular trauma score and ocular structural parameters in the assessment of healing visual acuity from ocular trauma / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the value of ocular trauma score(OTS), initial visual acuity, and ocular structural parameters in the assessment of healing visual acuity from ocular trauma.METHOD: A total of 302 cases(302 eyes)of ocular trauma were selected as subjects, which were accepted and issued clear appraisal opinions by the Academy of Forensic Science from June 2015 to June 2021. The subjects were grouped according to the healing best corrected visual acuity(BCVA)from ocular trauma. Group Ⅰ included 63 cases(63 eyes)with BCVA <3.7; Group Ⅱ included 70 cases(70 eyes)with 3.7≤ BCVA <4.5; Group Ⅲ included 78 cases(78 eyes)with 4.5≤ BCVA <4.9; Group Ⅳ included 91 cases(91 eyes)with BCVA≥4.9. In addition, 77 cases(77 healthy eyes)of ocular trauma were selected as the control group, namely Group Ⅴ. The healing BCVA and ocular structural parameters from ocular trauma and theirs correlation were analyzed, and the random forest(RF)and support vector machine(SVM)model of healing visual acuity was established by the IBM SPSS Modeler 18.0.RESULTS: The initial visual acuity, OTS, the grading of corneas, lenses, and fundus, and the thickness of the retinal never fiber layer of ocular trauma patients were correlated with the healing BCVA(P<0.01). There were significant differences in ocular structural parameters among groups, except the central subfield thickness(P<0.001). The SVM model had higher accuracy of predicting healing visual acuity than the RF model, and the accuracy rate was over 80% when the error was within 0.15.CONCLUSION:OTS and ocular structural examination can provide effective information for the clinical forensic medicine appraisal of visual dysfunction after ocular trauma, and they are valuable in discriminating camouflage of visual dysfunction.

The Value of VR-PVEP in Objective Evaluation of Monocular Refractive Visual Impairment / 法医学杂志

OBJECTIVES@#To study the virtual reality-pattern visual evoked potential (VR-PVEP) P100 waveform characteristics of monocular visual impairment with different impaired degrees under simultaneous binocular perception and monocular stimulations.@*METHODS@#A total of 55 young volunteers with normal vision (using decimal recording method, far vision ≥0.8 and near vision ≥0.5) were selected to simulate three groups of monocular refractive visual impairment by interpolation method. The sum of near and far vision ≤0.2 was Group A, the severe visual impairment group; the sum of near and far vision <0.8 was Group B, the moderate visual impairment group; and the sum of near and far vision ≥0.8 was Group C, the mild visual impairment group. The volunteers' binocular normal visions were set as the control group. The VR-PVEP P100 peak times measured by simultaneous binocular perception and monocular stimulation were compared at four spatial frequencies 16×16, 24×24, 32×32 and 64×64.@*RESULTS@#In Group A, the differences between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at 24×24, 32×32 and 64×64 spatial frequencies were statistically significant (P<0.05); and the P100 peak time of normal vision eyes at 64×64 spatial frequency was significantly different from the simulant visual impairment eyes (P<0.05). In Group B, the differences between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at 16×16, 24×24 and 64×64 spatial frequencies were statistically significant (P<0.05); and the P100 peak time of normal vision eyes at 64×64 spatial frequency was significantly different from the simulant visual impairment eyes (P<0.05). In Group C, there was no significant difference between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at all spatial frequencies (P>0.05). There was no significant difference in the P100 peak times measured at all spatial frequencies between simulant visual impairment eyes and simultaneous binocular perception in the control group (P>0.05).@*CONCLUSIONS@#VR-PVEP can be used for visual acuity evaluation of patients with severe and moderate monocular visual impairment, which can reflect the visual impairment degree caused by ametropia. VR-PVEP has application value in the objective evaluation of visual function and forensic clinical identification.

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.

Research Progress of the Effects of Monocular Visual Impairment on Binocular Vision / 法医学杂志

Binocular vision refers to a progress of analysing and integrating the binocular visual signals into a whole and three-dimensional sensory perception by higher nerve centre. In this process, the interac-tion between the two eyes results in the changes of output signal, which is called binocular interaction. Through a series of subjective and objective experiments, it can be concluded that binocular interaction can be divided into three types: facilitation, summation and suppression, and the forms of binocular in-teraction in different visual states are different. In general, the visual signal is processed by binocular in-teraction, so that there are some differences between binocular vision and monocular vision. The extent of the difference can be affected by the damage of monocular vision and then affects the binocular vision. Thus, it is necessary for forensic scientists to further study the effects of the monocular visual impairment on visual function. Based on relevant data, this paper reviews the mechanism of the monocular visual impairment in binocular vision, the research methods and the application prospect in forensic science.

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.

Distribution of Formic Acid after Methanol Intoxication in Rats / 法医学杂志

OBJECTIVE@#To investigate concentration and distribution in blood and tissues of formic acid after methanol intoxication in rats.@*METHODS@#The Sprague-Dawley rats were divided into groups for control group and 3-day and 7-day intoxication treatment groups. The experimental groups were administered methanol by gavage with the initial dose of 8 mL/kg and followed with 4 mL/kg supplemental dose 24 h later. After 3 days and 7 days later, rats were killed by decapitation. Then samples of cardiac blood, liver, kidney, brain, heart and stomach of each group were collected. Formic acid concentrations were detected by high performance liquid chromatography.@*RESULTS@#Formic acid concentrations in tissues were higher than in blood. Compared with 3-day intoxication group, there was an increase formic acid of concentration in brain and stomach in 7-day intoxication group, while a decrease in liver and kidney (P < 0.05).@*CONCLUSION@#High performance liquid chromatography could be used to accurately detect formic acid. As the metabolite of methanol, formic acid accumulates in rat blood and tissues after intoxication and the concentrations in organs and tissues are obviously higher than in blood.

Correlation between contrast vision and sweep visual evoked potential acuity / 法医学杂志

OBJECTIVE@#To compare the correlation between contrast vision (LV) and sweep visual evoked potential acuity (SVEP-A) among people with emmetropia, mild myopia, and moderate myopia.@*METHODS@#The CV and SVEP-A were tested individually in 96 eyes from healthy young volunteers, including 37 eyes of emmetropia, 27 eyes of mild myopia, and 32 eyes of moderate myopia. The statistic analysis was done by ANOVA analysis and rank sum test.@*RESULTS@#(1) With the decrease of contrast, CV and SVEP-A decreased in every group. (2) At 100% contrast, the difference of CV between emmetropia and mild myopia had statistical significance (P<0.05). At 100%, 25% and 10% contrast, the difference of CV between emmetropia and moderate myopia had statistical significance (P<0.05). (3) In the same group, the difference of 100% and 25% contrast had statistical significance (P < 0.05). So was between 100% and 10% contrast. (4) At 100% and 10% contrast, the difference of CV and SVEP-A had statistical significance (P < 0.05).@*CONCLUSION@#The CV of myopia relates to many factors including ametropia and fundus lesions. The correction of ametropia is important to the values of CV and SVEP-A.

Expression and mechanism of alphaB-crystallin in retina and extraocular tissues and organs / 法医学杂志

alphaB-crystallin is the structural protein of vertebrate lens, which is widely expressed in non-lens tissue. As one of the heat shock protein family members, alphaB-crystallin possesses biological properties of molecular chaperones and anti-apoptotic effects. Multi-factor injuries, such as retinopathy, inflammation and nervous system diseases, have a closely relationship with alphaB-crystallin. This paper reviews the research progress of the expression and mechanism of alphaB-crystallin in retina and extraocular tissues and organs.

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.

Changes of oscillatory potentials of electroretinogram after methanol intoxication in rats / 法医学杂志

OBJECTIVE@#To study the characters of oscillatory potentials (OPs) of electroretinogram (ERG) after methanol intoxication in rats.@*METHOD@#The SD rat models of methanol intoxication were established and divided into control group, 3-day intoxication group, 7-day intoxication group. The changes of OPs of ERG were recorded in a dark room.@*RESULTS@#The total amplitudes of 3-day and 7-day intoxication groups decreased approximately 50% compared with that of the control group, while the schedule delayed approximately 16% and 61%, respectively.@*CONCLUSION@#The characters of methanol intoxication in rats included delay in schedule and decline in the total amplitude of OPs.

Multifocal visual electrophysiology in visual function evaluation / 法医学杂志

Multifocal visual electrophysiology, consisting of multifocal electroretinography (mfERG) and multifocal visual evoked potential (mfVEP), can objectively evaluate retina function and retina-cortical conduction pathway status by stimulating many local retinal regions and obtaining each local response simultaneously. Having many advantages such as short testing time and high sensitivity, it has been widely used in clinical ophthalmology, especially in the diagnosis of retinal disease and glaucoma. It is a new objective technique in clinical forensic medicine involving visual function evaluation of ocular trauma in particular. This article summarizes the way of stimulation, the position of electrodes, the way of analysis, the visual function evaluation of mfERG and mfVEP, and discussed the value of multifocal visual electrophysiology in forensic medicine.

Correlativity between projected visual chart vision and contrast vision / 法医学杂志

OBJECTIVE@#To study the correlativity between the projected visual chart vision ("projector vision" in this paper) and the measured values of contrast vision, and to explore the application of contrast vision in identifying visual impairment after eye injury in the clinical forensic medicine.@*METHODS@#One hundred and twenty nine eyes of seventy-nine young volunteers were collected for examination both of projector vision and contrast vision. In the examination of contrast vision, the contrast of optotypes were set to 100%, 25% and 10%, respectively. The correlativity of both collected experimental data were statistically analyzed.@*RESULTS@#Projector vision was consistent with 100% contrast vision. There was a close and positive correlation between the contrast of optotypes and measured vision values. Under the same contrast of optotypes, projector vision presented a linear correlation with the average value of contrast vision.@*CONCLUSION@#There is a close correlation between projector vision and contrast vision. The contrast vision can be applied to judicial identification in the clinical forensic medicine.

Electroretinogram and histopathologic changes of the retina after methanol intoxication / 法医学杂志

In order to study the functional and structural alterations of the retina in SD rat model after methanol intoxication, 35 rats were divided randomly into five groups administrated with saline, 3-day high dose, 7-day high dose, 3-day low dose and 7-day low dose methanol separately. The retinal function of each group was assessed by flash electroretinogram (F-ERG) 3 and 7 days after methanol poisoning. The microstructure and ultrastructure of the retina were observed at the same time. The high-dose methanol intoxication induced irreversible retinal functional and structural damages 3 days after poisoning, which included prolonged latency and reduced amplitude of the Max-reaction of F-ERG. These injuries were aggravated 7 days after poisoning. Meanwhile, the latency and amplitude of the Cone-reaction of F-ERG were also affected 3 days after poisoning, but there were no further worsening tendency 7 days after poisoning. The retinal histological analysis showed cellular edema, heteromorphy and disarrangement, tissular loosen of the inner nuclear layer and photoreceptors layer. The mitochondrial damage began at the photoreceptors layer and developed further into the inner nuclear layer. The low-dose methanol intoxication only caused transient damage of the retina. Our results showed that the function and structure of the photoreceptor and inner nuclear layer were the primary target of methanol intoxication and that the rod cells were more sensitive to methanol intoxication than the cone cells. The mitochondrial damage developed from outer layer to inner layer of the retina.

Application of contrast vision in identifying the malingering decreased vision / 法医学杂志

OBJECTIVE@#To study the application value of contrast vision in identifying the malingering decreased vision in the practice of clinical forensic medicine.@*METHODS@#Thirty-one young and middle aged volunteers were selected and divided randomly into group 1 (16 persons with 32 eyes) and group 2 (15 persons with 30 eyes). The optotype contrast was 100%, 25%, 10% and 5%, respectively. The contrast vision of group 1 was tested. The contrast vision of group 2 was tested as follows: (1) the volunteers cooperated without inspector's interference; (2) the volunteers cooperated under inspector's interference; (3) the volunteers disguised decreased vision without inspector's interference; (4) the volunteers disguised decreased vision under inspector's interference. The data was then analyzed by statistics.@*RESULTS@#There was a close correlation between contrast vision and contrast. As the contrast decreased, the vision acuity also decreased. The contrast vision curve of former two methods showed a good reproducibility while the contrast vision curve of latter two methods had a bad reproducibility.@*CONCLUSION@#The repetition of contrast curve with or without inspector's interference can be used to discriminate malingering vision. The acquired contrast curves can be provided to the court as direct evidence and can help enhance the verification conclusion.

Features of blood supply and results of transarterial infusion and embolization in spinal metastases / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the features of blood supply and results of transarterial infusion and embolization in spinal metastases.</p><p><b>METHODS</b>Forty-one patients with spinal metastasis received transarterial infusion and embolization between March 2001 and June 2008. The inclusion criteria were: The metastatic lesion caused back pain; The metastatic lesion involved vertebra at or below T3 level. There were 29 males and 12 females with a mean age of 56.0 (33 - 71) years. Epirubicin was used as the chemotherapeutic agent. Lipoid Ultra-Fluid, Contour SE or gelfoam particles were used as embolitic material.</p><p><b>RESULTS</b>The technical success of therapy was achieved in 52 vertebrae (100%) including 14 thoracic, 35 lumbar and 3 sacral vertebrae. 105 arteries were used for infusion and embolization (16 intercostal arteries, 78 lumbar arteries, 4 iliolumbar arteries, 4 branches of iliac arteries, and 3 median sacral arteries). Lipoid Ultra-Fluid (2 - 8 ml) was used in 15, Contour SE (300 approximately 500 microm, 20 - 100 mg) in 20, and gelfoam particles in 33 arteries. Three days after treatment, complete pain relief (CR) was achieved in 17 patients, partial pain relief (PR) in 20, and moderate pain relief (MR) in 4, with an effective rate of 90.2%. Two weeks after treatment, CR was achieved in 17 patients, PR in 21, and MR in 3, with an effective rate of 92.7%. No adverse nervous system effect occurred. 16 patients developed swelling and pain of normal tissues which were alleviated after symptomatic treatment.</p><p><b>CONCLUSION</b>Transarterial infusion and embolization is an effective therapy in relieving pain resulting from spinal metastases.</p>

Advancement of methanol poisoning mechanism research / 法医学杂志

The methanol poisoning by oral intake or skin contact occurs occasionally, which may have serious consequences including blindness and/or death. Methanol and its metabolites, formaldehyde and formic acid, are associated with metabolic acidosis, visual dysfunction and neurological symptoms. At present, the mechanism of methanol poisoning primarily focuses on the cell hypoxia, the alteration of structure and biological activity induced by free radical and lactic acid. Meanwhile, methanol poisoning causes changes in the balance between the production of free radicals and antioxidant capacity and in the proteases-protease inhibitors system, which lead to a series of disturbances.

The relationship between eyeball structure and visual acuity in high myopia / 法医学杂志

OBJECTIVE@#To explore the relationship between eyeball structure and visual acuity in high myopia.@*METHODS@#Totally, 152 people (283 eyeballs) with different levels of myopia were tested for visual acuity, axial length, and fundus. All cases were classified according to diopter, axial length, and fundus. The relationships between diopter, axial length, fundus and visual acuity were studied. The mathematical models were established for visual acuity and eyeball structure markers.@*RESULTS@#The visual acuity showed a moderate correlation with fundus class, comus, axial length and diopter ([r] > 0.4, P < 0.000 1). The visual acuity in people with the axial length longer than 30.00 mm, diopter above -20.00 D and fundus in 4th class were mostly below 0.5. The mathematical models were established by visual acuity and eyeball structure markers.@*CONCLUSION@#The visual acuity should decline with axial length extension, diopter deepening and pathological deterioration of fundus. To detect the structure changes by combining different kinds of objective methods can help to assess and to judge the vision in high myopia.

Effects of temporal frequency on the sweep pattern visual evoked response acuity / 法医学杂志

OBJECTIVE@#To investigate the changes of sweep pattern visual evoked response (SPVER) acuity in different temporal frequency.@*METHODS@#The persons were collected and divided into the low visual acuity group (71 eyes) and the high visual acuity group (92 eyes). The eyes were stimulated with different temporal frequency (8.5 Hz, 10 Hz, 15 Hz and 20 Hz, respectively) and the same series of spatial frequency. The accuracy of SPVER acuity in different temporal frequency was evaluated by compare the SPVER acuity with the subjective vision.@*RESULTS@#In the low visual acuity group, there was a good correlation between the SPVER acuity and the subjective vision applying the spatial frequency of the group. In the high visual acuity group, the SPVER acuity was lower than the subjective vision. SPVER acuity showed a good correlation with the subjective vision at the temporal frequency of 10 Hz in two groups.@*CONCLUSION@#The temporal frequency can influence SPVER accuracy, so it is necessary to select the suitable stimulation condition in forensic practice.