Research status and prospect on the cerebral vision in myopic patients / 中华实验眼科杂志

The visual signal generated by the eye receiving external light stimulation reaches the visual center through the visual pathway and is processed and integrated by the visual center to form a subjective sensation called cerebral vision.Cerebral vision reflects the function of the whole visual nervous system from the retina to the visual cortex.Abnormal cerebral vision has been found in myopes using electrophysiology, magnetic resonance imaging (MRI) and functional near-infrared spectroscopy (fNIRS). The abnormal electrophysiological results are mainly found in patients with high myopia and pathological myopia.MRI shows abnormal changes in the structure and function of several vision-related brain regions in patients with high myopia.Recently, by applying near-infrared brain function imaging technology combined with self-developed equipment, our team conducted a series of studies on the brain function of myopic patients and found that adult patients with moderate myopia and patients with pathological myopia have the abnormal cerebral vision.The mechanism of neural regulation of eye accommodation in myopic children needs further investigation.In this article, we reviewed the current status and outlook of myopic brain vision research in terms of myopia classification, myopic brain vision research methods, and myopic visual electrophysiology, MRI, and fNIRS studies.

Distinction and processing of common artifact in clinical visual electrophysiology / 中华实验眼科杂志

Objective:To explore the common causes and solutions for artifacts in clinical visual electrophysiological examination.Methods:A cross-sectional study was performed.The clinical visual electrophysiological examination results of 25 001 cases were collected from 2012 to 2020 at the Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University). Artifacts were identified and analyzed according to the standard waveform provided by the International Society for Clinical Electrophysiology of Vision.The characteristics and causes of the artifact were analyzed.The solutions to reduce and eliminate the artifact were proposed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University) (No.KY2020053).Results:There were 60 typical artifacts identified among the 25 001 cases.Common causes of the artifacts were classified as three categories, the factors related to subjects, environment, or instruments.Among the 60 cases, 42(70.0%) were caused by tension in head and facial muscles of patients, 9(15.0%) due to blinking of patients, 4(6.7%) resulted from 50 Hz power frequency artifact, 2(3.3%) arisen from abnormal amplifier, and 3(5.0%) for other reasons.The strategies to avoid artifact were as follows.First, examiners could inform patients of the examination process in advance to help patients to relax and avoid the influencing factors, such as muscle tension in head and face, blinking, inattention and so on; second, high-quality 50 Hz hardware wave trap was recommended to reduce 50 Hz artifact, with good ground connection and removing of the high-power electrical appliances near the visual electrophysiological instrument; third, clean the skin sufficiently to reduce the reference electrode impedance to less than 1 kΩ.Conclusions:There is a variety of artifact waveforms and causes.The technicians should make correct judgments and handle the artifact in time to provide more accurate examination results.The doctors should know about artifact, which is helpful for better interpretation of visual electrophysiological examination reports.

Screening, identification and functional analysis of differential expression genes in rat visual cortex after monocular deprivation by RNA-Seq technique / 中华实验眼科杂志

Objective:To screen differentially expressed genes (DEGs) in rat visual cortex after monocular deprivation by RNA sequencing technology, and to analyze the function of the DEGs.Methods:Eighteen 14-day-old SD rats were randomly divided into blank control group and monocular deprivation model group according to random number table method, with 9 rats in each group.The monocular deprivation model was established through lid suture of the right eye for 14 days.Patten visual evoked potential (PVEP) in the right eyes of the rats was recorded before and 14 days after modeling, respectively.Bilateral visual cortex tissues of the rats were dissected from the two groups, and specific genes associated with the pathogenesis of amblyopia were screened out for RNA-seq analysis.The biological functions of differentially expressed genes were evaluated by Gene Ontology (GO) enrichment analysis, and metabolic pathways involved were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.The use and care of the animals complied with ARVO statement.This study protocol was approved by an Ethics Committee of Gansu University of Chinese Medicine (No.2016-58).Results:Compared with blank control group, the latency of P 100 wave was significantly prolonged, and the amplitude was reduced in the eyes of monocular deprivation model group (both at P<0.05). Forty DEGs in the left visual cortex and 63 DEGs in the right visual cortex were determined, among which 9 genes were overlapped.GO analysis indicated that the DEGs were mainly involved in biological processes, such as DNA-templated transcription, glutamate secretion, transcriptional regulation of RNA polymerase Ⅱ promoter, protein phosphorylation etc., as well as molecular functions, such as DNA binding, ATP binding, protein serine/threonine kinase activity, calcium ion binding, zinc ion binding, phospholipase A 2 activity, nucleic acid binding and cell components involved in the formation of intracellular and membrane of endoplasmic reticulum.The abnormal expressions of Grm2 and Pla2g2a genes might be closely associated with visual function impairment. Grm2 gene was mainly involved in visual signaling pathway processes including glutamate synapse, long-term potentiation (LTP), long-term depression (LTD) etc. Pla2g2a gene was mainly involved in α-linolenic acid metabolism and arachidonic acid pathway. Conclusions:There are abnormal expressions of genes in the bilateral visual cortices of monocular deprivation rats in the sensitive period of visual development, mainly leading to the disorder of visual signal transduction pathway.Metabolic pathway changes based on specific response gene regulation may be one of the important molecular biological mechanisms in the pathogenesis of amblyopia.

Grating visual acuity impairment assessed by sweep visually evoked potentials in children with optic pathway tumors unable to perform optotype acuity tests / Deficiência na acuidade visual de grades avaliada pelos potenciais visuais evocados de varredura em crianças com tumores da via óptica incapazes de informar a acuidade de optotipos

ABSTRACT Purpose: To determine visual impairment due to optic pathway tumors in children unable to perform recognition acuity tests. Methods: Grating visual acuity scores, in logMAR, were obtained by sweep visually evoked potentials (SVEP) in children with optic pathway tumors. The binocular grating visual acuity deficit was calculated by comparison with age-based norms and then assigned to categories of visual impairment as mild (from 0.10 to 0.39 logMAR), moderate (from 0.40 to 0.79 logMAR), or severe (≥0.80 logMAR). Interocular differences were calculated by subtraction and considered increased if >0.10 logMAR. Results: The participants were 25 children (13 boys; mean ± SD age, 35.1 ± 25.9 months; median age, 32.0 months) with optic pathway tumors (24 gliomas and 1 embryonal tumor), mostly located at the hypothalamic-chiasmatic transition (n=21; 84.0%) with visual abnormalities reported by parents (n=17; 68.0%). The mean grating acuity deficit was 0.60 ± 0.36 logMAR (median, 0.56 logMAR). Visual impairment was detected in all cases and was classified as mild in 10 (40.0%), moderate in 8 (32.0%), and severe in 7 (28.0%) children, along with increased interocular differences (>0.1 logMAR) (n=16; 64.0%). The remarkable ophthalmological abnormalities were nystagmus (n=17; 68.0%), optic disc cupping and/or pallor (n=13; 52.0%), strabismus (n=12; 48.0%), and poor visual behavior (n=9; 36.0%). Conclusion: In children with optic pathway tumors who were unable to perform recognition acuity tests, it was possible to quantify visual impairment by sweep-visually evoked potentials and to evaluate interocular differences in acuity. The severity of age-based grating visual acuity deficit and interocular differences was in accordance with ophthalmological abnormalities and neuroimaging results. Grating visual acuity deficit is useful for characterizing visual status in children with optic pathway tumors and for supporting neuro-oncologic management.(AU)

RESUMO Objetivo: Determinar o grau de deficiência visual em crianças com tumores da via óptica incapazes de informar a acuidade visual de reconhecimento. Método: A acuidade visual de grades, em logMAR, foi estimada por potenciais visuais evocados de varredura em crianças com tumores das vias ópticas. O déficit da acuidade visual de grades binocular foi calculado em relação ao valor mediano normativo esperado para a idade e a deficiência visual, classificada como leve (0,10 a 0,39 logMAR), moderada (0,40 a 0,79 logMAR) ou grave (≥0,80 logMAR). Diferenças inter-oculares foram calculadas por subtração e consideradas aumentadas se >0,10 logMAR. Resultados: Foram avaliadas 25 crianças (13 meninos; média de idade ± DP=35,1± 25,9 meses; mediana=32,0 meses) com tumores da via óptica (24 gliomas e 1 tumor embrionário) localizados particularmente na transição hipotalâmico-quiasmática (n=21; 84,0%) e com anormalidades visuais detectadas pelos pais (n=17; 68,0%). A média do déficit da acuidade de grades foi 0,60 ± 0,36 logMAR (mediana=0,56 logMAR). Observou-se deficiência visual leve em 10 (40,0%), moderada em 8 (32,0%) e grave em 7 (28,0%), além de aumento da diferença interocular da acuidade visual (n=16; 64,0%). As principais alterações oftalmológicas encontradas foram: nistagmo (n=17; 68,0%), aumento da escavação do disco óptico e/ou palidez (n=13; 52,0%), estrabismo (n=12; 48,0%) e comportamento visual pobre (n=9; 36,0%). Conclusão: Em crianças com tumor da via óptica e incapazes de responder aos testes de acuidade visual de reconhecimento, foi possível quantificar deficiência visual por meio dos potenciais visuais evocados de varredura e avaliar a diferença interocular da acuidade visual de grades. A gravidade do déficit da acuidade visual de grades relacionado à idade e a diferença interocular da acuidade visual de grades foram congruentes com alterações oftalmológicas e neuroimagem. O déficit da acuidade visual de grades foi útil à caracterização do estado visual em crianças com tumores da via óptica e ao embasamento da assistência neuro-oncológica.(AU)

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.

Regulation of acupuncture on NMDAR1 mRNA expression in visual cortex of monocularly-deprived rats / 针灸推拿医学（英文版）

Objective: To explore the molecular biological mechanism of acupuncture in intervening visual deprivation. Methods: Forty-eight 2-week old Wistar rats were randomly divided into a normal group, a model group, and 6 acupuncture groups (group C1: acupuncture at the unaffected side in early stage; group C2: acupuncture at the affected side in early stage; group D1: acupuncture at the unaffected side in mid-stage; group D2: acupuncture at the affected side in mid-stage; group E1: acupuncture at the unaffected side in late stage; group E2: acupuncture at the affected side in late stage) by the random number table, 6 rats in each group. Rats in the normal group didn’t receive any interventions. The rat model of deprivation amblyopia was established by unilateral eyelid suture in the model group and each acupuncture group. After successful modeling, rats in model group didn’t receive any treatments; rats in the acupuncture groups received acupuncture intervention which began respectively on the 3rd, 12th and 21st day after modeling. Pattern visual evoked potential (P-VEP) and N-methy D-aspartatreceptor-1 (NMDAR1) mRNA expression in visual cortex area 17 were detected at the end of acupuncture intervention in each group. Results: After the intervention, the P-VEP waveform was significantly changed, with a significantly delayed P100 value (P0.05). Conclusion: P-VEP waveform is abnormal and NMDAR1 mRNA expression in visual cortex area 17 is decreased in rats with monocularly-deprived amblyopia. Acupuncture in the sensitive period can significantly regulate the abnormal P-VEP waveform and the down-regulate the NMDAR1 mRNA expression of the visual cortex of rats with monocularly-deprived amblyopia. Early treatment in the sensitive period should be the key to obtaining the curative effect.

Dysfunction in the fellow eyes of strabismic and anisometropic amblyopic children assessed by visually evoked potentials / Alterações dos potenciais visuais evocados nos olhos contralaterais de crianças com ambliopia estrabísmica e anisometrópica

ABSTRACT Purpose: To evaluate visual acuity and transient pattern reversal (PR) visual evoked potentials (VEPs) in the fellow eyes of children with strabismic and/or anisometropic amblyopia. Methods: Children diagnosed with strabismic and/or anisometropic amblyopia were recruited for electrophysiological assessment by VEPs. Monocular grating and optotype acuity were measured using sweep-VEPs and an Early Treatment Diabetic Retinopathy Study chart, respectively. During the same visit, transient PR-VEPs of each eye were recorded using stimuli subtending with a visual angle of 60', 15', and 7.5'. Parameters of amplitude (in μV) and latency (in ms) were determined from VEP recordings. Results: A group of 40 strabismic and/or anisometropic amblyopic children (22 females: 55%, mean age= 8.7 ± 2.2 years, median= 8 years) was examined. A control group of 19 healthy children (13 females: 68.4%, mean age= 8.2 ± 2.6 years, median= 8 years) was also included. The fellow eyes of all amblyopes had significantly worse optotype acuity (p=0.021) than the control group, regardless of whether they were strabismic (p=0.040) or anisometropic (p=0.048). Overall, grating acuity was significantly worse in the fellow eyes of amblyopes (p=0.016) than in healthy controls. Statistically prolonged latency for visual angles of 15' and 7.5' (p=0.018 and 0.002, respectively) was found in the strabismic group when compared with the control group. For the smaller visual stimulus (7.5'), statistically prolonged latency was found among all fellow eyes of amblyopic children (p<0.001). Conclusions: The fellow eyes of amblyopic children showed worse optotype and grating acuity, with subtle abnormalities in the PR-VEP detected as prolonged latencies for smaller size stimuli when compared with eyes of healthy children. These findings show the deleterious effects of amblyopia in several distinct visual functions, mainly those related to spatial vision.

RESUMO Objetivo: Avaliar a acuidade visual e os potenciais visuais evocados transientes por reversão de padrões no olho contralateral de crianças com ambliopia estrabísmica e/ou anisometrópica. Métodos: Foram avaliados os potenciais visuais evocados de crianças com ambliopia estrabísmica e/ou anisometrópica. As acuidades visuais monoculares de grades e de optotipos foram mensuradas utilizando o PVE de varredura e a tabela EDTRS, respectivamente. Na mesma visita, foram registrados os PVERP transients de cada olho usando estímulos de ângulo visual de 60'; 15' e 7,5'. Parâmetros de amplitude (em microvolts) e latência (em milissegundos) foram determinados para os registros dos potenciais visuais evocados. Resultados: Um grupo de 40 crianças amblíopes estrábicas e/ou anisometrópicas (22 meninas - 55%, media idade= 8,7 ± 2,2, mediana= 8) foi examinado. Um grupo de 19 crianças saudáveis (13 meninas 68,4%, media idade= 8,2 ± 2,6, mediana= 8) de controle também foi incluído. A acuidade visual por optotipos foi significativamente pior (p=0,021) nos olhos contralaterais de todos os amblíopes, quando comparado com o grupo controle, independentemente se estrábico (p=0,040) ou anisometrópico (p=0,048). No geral, a acuidade visual por grades foi significativamente pior nos olhos contralaterais dos amblíopes (p=0,016), quando comparados com o grupo controle. Foi encontrada latência estatisticamente prolongada para ângulos visuais de 15' (p=0,018) e 7,5' (p=0,002) no grupo estrábico, quando comparado com o grupo controle. Para o menor estímulo visual (7,5') foi encontrada latência estatisticamente prolongada nos olhos contralaterais de todas crianças amblíopes (p<0,001). Conclusões: Os olhos contralaterais de crianças amblíopes mostraram pior acuidade visual de optotipo e de resolução de grades, com alterações sutis nos PVERP, detectadas pelas latências prolongadas para estímulos de menor tamanho, quando comparados com os olhos de crianças saudáveis. Estes resultados mostram os efeitos deletérios da ambliopia em várias funções visuais distintas, principalmente relacionadas à visão espacial.

Pattern-reversal visual evoked potentials as a diagnostic tool for ocular malingering / Potenciais visuais evocados por padrões reversos como uma ferramenta diagnóstica de simulação

ABSTRACT Purpose: To investigate the contributions of transient pattern-reversal visual evoked potentials in the diagnosis of ocular malingering at a Brazilian university hospital. Methods: Adult patients with suspected malingering in one or both eyes were referred for visual evoked potential testing. Data from patients' medical records were reviewed and analyzed retrospectively. Data analysis included the distance optotype visual acuity based on a ETDRS retro-illuminated chart and the transient pattern-reversal visual evoked potential parameters of latency (milliseconds) and amplitude (microvolts) for the P100 component, using checkerboards with visual subtenses of 15' and 60'. Motivations for malingering were noted. Results: The 20 subjects included 11 (55%) women. Patient ages ranged from 21 to 61 years (mean= 45.05 ± 11.76 years; median= 49 years). In 8 patients (6 women), both eyes exhibited reduced visual acuity with normal pattern-reversal visually evoked potential parameters (pure malingerers). The remaining 12 patients (7 men) exhibited reduced vision in only 1 eye, with simulated reduced vision in the contralateral eye (exaggerators). Financial motivation was noted in 18 patients (9 men). Conclusion: Normal pattern-reversal visually evoked potential parameters with suspected ocular malingering were observed in a 20 patient cohort. This electrophysiological technique appeared to be useful as a measure of visual pathway integrity in this specific population.

RESUMO Objetivo: Investigar a contribuição dos potenciais visuais evocados por padrões reversos no diagnóstico de simulação de baixa de visão em um hospital universitário do Brasil. Métodos: Um grupo de pacientes adultos com suspeita de simulação de baixa de visão em um ou ambos os olhos foi avaliado e os dados analisados retrospectivamente. Foram medidos: acuidade visual de optotipos informada para longe utilizando a tabela ETDRS, parâmetros dos potenciais visuais evocados por padrões reversos de latência (milissegundos) e amplitude (microvolts) para o componente P100 com estímulos de ângulos visuais de 15' e 60'. A motivação do paciente para a simulação foi anotada. Resultados: Os participantes foram 20 indivíduos com 11 (55%) do sexo feminino. A idade variou de 21 a 61 anos (média= 45,05 ± 11,76 anos; mediana= 49 anos). Em 8 pacientes (6 mulheres) ambos os olhos tinham acuidade visual reduzida com parâmetros dos potenciais visuais evocados por padrão reverso normais para ambos os olhos (simuladores puros). Uma subsérie separada de 12 pacientes (7 homens) tinha visão reduzida em apenas um olho e estavam simulando redução da visão no outro olho (exacerbadores). A motivação financeira foi observada em 18 pacientes (9 homens). Conclusões: Parâmetros dos potenciais visuais evocados por padrões reversos normais foram encontrados neste grupo de 20 pacientes com suspeita de simulação. Esta técnica eletrofisiológica pode ser útil como uma medida da integridade do sistema visual nesta população de doentes.

Forensic Application of Microperimetry and Visual Evoked Potential in Macular Disease / 法医学杂志

Objective To find the correlation between real best corrected visual acuity (BCVA) and test-ing results of microperimetry and visual evoked potential (VEP) and to explore a newmethod in record-ing BCVAin macular disease. Methods Sixty-two patients with macular disease (macular disease group, 62 eyes) and eighteen healthy volunteers (control group, 36 eyes) had BCVA, microperimetry and VEP recorded. Results (1) By microperimetry, the values of retinal mean sensitivity and fixation percentage in macular disease group were lower than that in control group. The bicurve ellipse area in macular dis-ease group was higher than that in control group. By V EP, P100 amplitude under 0.5 cpd and 2 cpd in macular disease group were significantly higher than that in control group and the latency was prolonged (P<0.05). (2) In macular disease group, BCVAhad significant positive correlation with retinal mean sen-sitivity, bicurve ellipse area, macular central 2°and 4°fixation percentage, respectively (P<0.05). There was a significant correlation between retinal mean sensitivity and P100 amplitude (P<0.05). (3) multiple linear regression equation was y=0.053 x1+0.008 x3+3.897 (y was BCVA, while x1 was retinal mean sensi-tivity and x3 was P100 amplitude under 2 cpd). Conclusion C ombined use of microperimetry and VEP is useful in the assessment of BCVAin macular disease.

The characteristics of visual P300 event-related potentials in children with mental retardation and the correlation with intelligent quotient / 中国医师杂志

Objective To explore the characteristics of visual P300 event-related potentials (ERP) in children with mental retardation and evaluate the correlations between visual P300 in event-related potentials and intelligent quotient.Methods Thirty children with mental retardation were selected as the test group who were inpatients or saw a doctor in the Department of Rehabilitation of Hunan Children Hospital.At the same time,thirty normal children were selected as the control group who saw a doctor in the Department of Child Healthcare of Hunan Children Hospital.Two groups had no statistically significant difference in sex and age (P ＞ 0.05) and were comparable.All children were administered with the Wechsler intelligence test in the Department of Child Healthcare and the visual event-related potential test in the Department of Rehabilitation.The results of the visual P300 latency and amplitude were analyzed.Another,the relevance between intelligent quotient (IQ) and P300 latency and amplitude were also compared by statistics.Results Compared to the control group,the visual P300 latency in children with mental retardation (MR) was apparently longer and the amplitude decreased significantly in children with MR,with a statistically significant difference between two groups(P ＜0.05).P300 latency in MR expected negative correlation with intelligent quotient and the amplitude in MR expected no correlation with intelligent quotient.Conclusions P300 latency and amplitude of ERP could objectively reflect cognitive function in children with MR,could be regarded as one of the objective measurement in the evaluation of cognitive function in children with MR.It can be used as an objective electrophysiological index for assisting in the diagnosis of mental retardation of children in clinic.

Applications of visual evoked potentials and Fourier-domain optical coherence tomography in Parkinson's disease: a controlled study / Potenciais evocados visuais e tomografia de coerência óptica com domínio de Fourier na doença de Parkinson: um estudo controlado

Purpose: The goal of this cross-sectional observational study was to quantify the pattern-shift visual evoked potentials (VEP) and the thickness as well as the volume of retinal layers using optical coherence tomography (OCT) across a cohort of Parkinson's disease (PD) patients and age-matched controls. Methods: Forty-three PD patients and 38 controls were enrolled. All participants underwent a detailed neurological and ophthalmologic evaluation. Idiopathic PD cases were included. Cases with glaucoma or increased intra-ocular pressure were excluded. Patients were assessed by VEP and high-resolution Fourier-domain OCT, which quantified the inner and outer thicknesses of the retinal layers. VEP latencies and the thicknesses of the retinal layers were the main outcome measures. Results: The mean age, with standard deviation (SD), of the PD patients and controls were 63.1 (7.5) and 62.4 (7.2) years, respectively. The patients were predominantly in the initial Hoehn-Yahr (HY) disease stages (34.8% in stage 1 or 1.5, and 55.8 % in stage 2). The VEP latencies and the thicknesses as well as the volumes of the retinal inner and outer layers of the groups were similar. A negative correlation between the retinal thickness and the age was noted in both groups. The thickness of the retinal nerve fibre layer (RNFL) was 102.7 μm in PD patients vs. 104.2 μm in controls. Conclusions: The thicknesses of retinal layers, VEP, and RNFL of PD patients were similar to those of the controls. Despite the use of a representative cohort of PD patients and high-resolution OCT in this study, further studies are required to establish the validity of using OCT and VEP measurements as the anatomic and functional biomarkers for the evaluation of retinal and visual pathways in PD patients. .

Objetivo: Este estudo observacional transversal controlado visou quantificar os potenciais evocados visuais com estímulo de padrões alternantes (PEV), a espessura e o volume das camadas retinianas com tomografia de coerência óptica (TCO) num grupo de pacientes com doença de Parkinson (DP). Métodos: Quarenta e três pacientes com DP e 38 controles. Procedimentos: pacientes e controles foram submetidos a exames neurológico e oftalmológico detalhados, sendo incluídos pacientes com DP idiopática e excluídos casos com glaucoma ou aumento da pressão intraocular. Todos os participantes foram estudados com PEV e TCO de Fourier, sendo quantificadas as latências de P100, a espessura e o volume das camadas retinianas interna e externa. Resultados: A média das idades e desvio-padrão dos pacientes com DP e controles foram respectivamente 63,1(7,5) e 62,4 (7,2) anos. Os pacientes com DP situaram-se predominantemente nos estágios iniciais de Hoehn-Yahr (34.8% no estágio 1 ou 1.5; 55.8 % no estágio 2). Não foram observadas diferenças entre os dois grupos quanto às latências dos PEV, a espessura e o volume das camadas retinianas. Observamos uma correlação negativa entre a espessura das camadas retinianas e a idade em ambos os grupos. Não se observou diferença significativa quanto à espessura da camada retiniana das fibras do nervo óptico (CRFNO), que foi de 102,7 μm nos pacientes e 104,2 μm nos controles. Conclusões: A espessura das camadas retinianas, os PEV e a espessura da CRFNO foi semelhante nos pacientes com DP e controles. Apesar desse grupo representativo de pacientes com DP e da alta resolução da TCO utilizada neste estudo, mais estudos são necessários para estabelecer o papel da TCO e dos PEV como biomarcadores anatômico e funcional na avaliação ...

MR diffusion tensor imaging of optic nerve in anterior ischemic optic neuropathy at 3.0 T and correlation between diffusion tensor imaging and pattern visual evoked potential / 中华放射学杂志

Objective To study the value of MR diffusion tensor imaging (MR-DTI)using a 3.0 T scanner in anterior ischemic optic neuropathy(AION).Methods A total of 26 patients suffering from unilateral subacute AION were examined using DTI and pattern visual evoked potential(P-VEP).The parameters values of optic nerves including fractional anisotropy (FA),ADC,vertical diffusivity (λ⊥),paralleldiffusion (λ//),P100 value and amplitude were obtained.Paired t-tests were used for comparing the FA,ADC,λ⊥,and λ// values of the two groups.Correlations of DTI parameters and P-VEP parameters were analysed by using the Pearson rank correlation analysis.Results The values of FA,ADC,λ//,and λ_ in the affected nerve were 0.28±0.07,(1.43±0.20) ×103 mm2/s,(1.79±0.16) ×10-3 mm2/s,and (1.25±0.17) ×10-3 mm2/s respectively,and the corresponding values of unaffected nerve were 0.57±0.05,(1.04±0.17) ×10-3 mm2/s,(1.71 ±0.19) × 10-3 mm2/s,and (0.75±0.08) × 10-3 mm2/s respectively.Compared to unaffected contralateral nerves,the mean FA was reduced,the mean ADC,λ⊥ were increased in the affected nerves(t=-19.269,10.537,15.301,P＜0.01).However,there were no significant difference of the λ//(t=l.632,P＞0.05).There was significant negative correlation between ADC and P-VEP amplitude in affected optic nerves (r=-0.722,P＜0.01).There was moderate negative correlation between λ⊥ and P-VEP amplitude in affected optic nerves (r=-0.634,P＜0.01).There was moderate correlation between FA and P-VEP amplitude (r=0.539,P＜0.01).There was no correlation between λ// and P-VEP amplitude.There was moderate negative correlation between FA and P-VEP P100 latency(r =-0.619,P＜0.01).Conclusions DTI can sensitively detect diffusional abnormality of anterior ischemic optic neuropathy.DTI could be used as a supplemental way in the assessment of AION.

Visual evoked potentials (VEP) and visual acuity improvement after cytidine 52 -diphosphocholine (CDP-Choline) therapy in amblyopic patient / Melhora do potencial evocado visual (PEV) e da acuidade visual em paciente amblíope tratado com citidina difosfato colina

Citicoline may be used in many neurological disorders. Combined treatment of citicoline with patching in amblyopia has previously been researched. The purpose of this paper is to illustrate the effect of citicoline in non-patching amblyopic patient. A 11-year-old amblyopic boy underwent complete ophthalmological examinations, including VEP with flash and pattern stimulus. Two averages of 100 sweep were performed for flash stimulus. Pattern reversal stimulus obtained with high contrast was performed with 60', 30' and 15' checks stimuli. The VEP was repeated 90 days later after a therapy with citicoline and vitamin and the results compared with the responses of the previous recording session. The visual acuity (VA) was 0,7 in the RE and 1,0 in the LE. The VEP pattern amplitude was normal in both eyes. Delayed in latency was detected for all spatial frequency stimulus (SFS) in the RE. Delay in latency was detected only for high SFS in the LE. After the treatment, the VA was 1,0 in both eyes. The latency was normalized with low SFS on the RE and with high SFS on the LE. The flash VEP was normal before and after the therapy. In conclusion, the citicoline demonstrated that it was effective in the treatment of amblyopic eye without patching. The VA and the VEP latency improvement demonstrated that the citicoline enhance the transmission of the electric impulse from retina to visual cortex. Further research is required to understand the immediate and long-term effect of coline treatment in amblyopic patients.

A citicolina pode ser utilizada em vários problemas neurológicos. O tratamento combinado de citicolina e oclusão na ambliopia já foi previamente relatado. O objetivo deste estudo é ilustrar o efeito da citicolina em paciente amblíope sem o tratamento oclusivo. Um menino de 11 anos de idade foi submetido a um exame oftalmológico completo incluindo PEV do tipo flash e do tipo padrão reverso. Para o PEV tipo flash, foram analisadas duas médias de 100 estímulos cada uma. Para o PEV do tipo padrão reverso, foram utilizados estímulos de alto contraste de 60', 30' e 15'. O PEV foi repetido 90 dias depois do tratamento com citicolina e vitaminas e os resultados comparados com os exames antes do tratamento. A acuidade visual era de 0,7 no olho direito e 1,0 no olho esquerdo. A amplitude do PEV era normal em ambos os olhos. Era presente um aumento da latência a todas as frequências espaciais de estimulação (FEE) no olho direito e somente à alta FEE no olho esquerdo. Após o tratamento, a acuidade visual era de 1,0 em ambos os olhos. A latência se normalizou à baixa FSS no olho direito e à alta FSS no olho esquerdo. O PEV tipo flash era normal antes e depois do tratamento. Em conclusão, a citicolina demonstrou ser eficaz no tratamento de olhos amblíopes sem oclusão. A melhora da acuidade visual e da latência do PEV demonstraram que a citicolina restaura a transmissão elétrica do impulso da retina ao cortex visual. Pesquisas futuras são necessárias para entender o efeito imediato e a longo prazo da citicolina no tratamento de pacientes amblíopes.

Effects of duration of surgery flash-induced visual evoked potentials in patients undergoing spinal surgery in prone position / 中华麻醉学杂志

Objective To investigate the effects of duration of surgery on flash-induced visual evoked potentials (VEP) in patients undergoing spinal surgery in prone position.Methods Eighty-two ASA Ⅰ or Ⅱ patients of both sexes aged 20-76 yr weighing 43-96 kg undergoing spinal surgery in prone position were divided into 3 groups according to the duration of surgery:group S≤2 h ( n =34) ; group M 2-4 h ( n =38) and group L≥4 h ( n =10).VEP was monitored using protektor VEP monitoring device (Xltek Co.,Canada).The latency,amplitude and recovery time of wave P100 were recorded before and 10 min after induction of anesthesia and at the end of surgery.Results Compared with group S,the amplitude of wave P1000 was significantly decreased at the end of surgery in group M,the lantency of wave P100 was significantly prolonged,while the amplitude of wave P100 was decreased at the end of surgery in group L ( P ＜ 0.05).Compared with group M,the lantency of wave P100 was significantly prolonged,while the amplitude of wave P100 was decreased at the end of surgery in group L ( P ＜ 0.05).Compared with groups S and M,the recovery time of wave P100 was significantly prolonged in group L ( P ＜0.05).There was no significant difference in the recovery time of wave P100 between groups S and M ( P ＞ 0.05).Conclusion Duration of surgery (≥4 h) can affect flash-induced VEP,the longer the duration,the stronger the effects.

Axonal electrovisiogram as an electrophysiological test to evaluate optic nerve and inner retina electrical potentials: findings in normal subjects / Eletrovisuograma axonal como teste eletrofisiológico na avaliação dos potenciais de ação do nervo óptico e da retina interna: achados em indivíduos normais

PURPOSES: To standardize and validate the technique of axonal electrovisiogram (AxEvg), defining its normative values and parameters and characterizing its findings in normal individuals. METHODS: We enrolled 140 normal individuals (280 eyes) divided into seven groups according to age, each one with 10 males and 10 females. The technique was based on monocular visual stimulation by a 0 dB intensity bright flash on Ganzfeld bowl at a presentation rate of 1.4 Hz. Golden cup electrodes were used and electrical waves were acquired after artifact rejection. For each amplitude and implicit time peak we calculated the mean, median, pattern deviation, minimum and maximum values and 95 percent confidence interval. RESULTS: Monocular visual stimulation with bright flash under mesopic conditions was the standard technical procedure established. The normal AxEvg waveform consists of an initial positive wave (named P1, with mean amplitude of 2.0 mV and mean implicit time peak of 23.1 ms) followed by a negative wave (named N1, with mean amplitude of -3.9 mV and mean implicit time peak of 41.4 ms). No significant differences were observed between males and females or between right and left eyes, but there was an increased P1 and N1 implicit time peaks according to age. Implicit time characteristics suggest that P1 wave represents an optic nerve electrical potential and N1 wave represents an inner retinal layers potential. CONCLUSIONS: AxEvg can be considered a pre-chiasmatic visual evoked potential capable to reliably record the electrical activity of optic nerve and inner retina. The findings suggest that AxEvg may be useful as an electrophysiological test in the diagnosis of neuroretinal diseases.

OBJETIVOS: Padronizar e validar a técnica de realização do eletrovisuograma axonal (EVA), definir seus valores normativos e caracterizar os achados em indivíduos normais. MÉTODOS: Estudo descritivo com 140 indivíduos (280 olhos) normais. Os participantes foram divididos em sete grupos de acordo com a idade, cada qual com 10 indivíduos do sexo masculino e 10 do sexo feminino. Definiu-se como técnica de exame a estimulação monocular por flash luminoso com intensidade de 0 dB na cúpula de Ganzfeld a uma frequência de 1,4 Hz. Foram utilizados eletrodos com cúpula de ouro e foram analisados os traçados elétricos obtidos após rejeição de artefatos. Para cada amplitude e tempo de culminação foram calculados a média, a mediana, o desvio-padrão, os valores mínimo e máximo e o intervalo de confiança de 95 por cento representando uma faixa de normalidade para os valores. RESULTADOS: A técnica de exame padronizada foi a estimulação visual monocular por flash em condições mesópicas. O traçado normal do eletrovisuograma axonal consistiu numa onda positiva inicial (P1, com amplitude média de 2,0 mV e tempo de culminação médio de 23,1 ms) seguida de uma onda negativa (N1, com amplitude média de -3,9 mV e tempo de culminação médio de 41,4 ms). Não foram observadas diferenças significativas entre os sexos e entre os olhos direito e esquerdo, mas os tempos de culminação de P1 e de N1 aumentaram proporcionalmente com a idade. CONCLUSÕES: O eletrovisuograma axonal é um exame de potencial visual evocado pré-quiasmático, capaz de registrar de forma confiável e reprodutível a atividade elétrica do nervo óptico e da retina interna, podendo ser utilizado na propedêutica eletrofisiológica na investigação de lesões neurorretinianas.

Clinical value of combined examination of transient and steady-state flash visual evoked potential / 中华全科医师杂志

The study intended to evaluate the combined examination of transient flash visual evoked potential (T-FVEP) and steady-state flash visual evoked potential (SS-FVEP) in diagnosis of optic neuropathy and macular disease. T-FVEP and SS-FVEP were examined in 22 cases (29 eyes) with optic neuropathy, 8 cases (9 eyes) with macular disease and 32 cases (32 eyes) of controls. The positive rates of T-FVEP and SS-FVEP in diagnosis of optic neuropathy were 83% and 100% respectively; that of combined examination was 100%. The positive rates of T-FVEP and SS-FVEP in diagnosis of macular disease were 5/9 and 7/9, and that of combined examination was 8/9. The positive rates of combined examination of T-FVEP and SS-FVEP in diagnosis of optic neuropathy and macular disease are higher than that of T-FVEP and SS-FVEP alone, and should be used routinely in the diagnosis of visual pathway disease.

Age norms for monocular grating acuity measured by sweep-VEP in the first three years of age / Estudo normativo de acuidade visual de resolução de grades medido pelo PVE de varredura nos três primeiros anos de vida

PURPOSE: To determine age norms for grating visual acuity and interocular acuity differences measured by the sweep-visually evoked potentials (VEP) technique in the first three years of life. METHODS: Monocular grating visual acuity was measured using the sweep-VEP in 67 healthy normal infants and children in the first 36 months of life. RESULTS: Sweep-VEP grating acuity ranged from 0.80 logMAR (20/125 Snellen equivalent) in the first month of life to 0.06 logMAR (20/20 Snellen equivalent) at 36 months of age. Lower normal limits (95th percentile limit) ranged from 0.95 logMAR (20/180) to 0.12 logMAR (20/25) with a progression of approximately 3 octaves in the first 36 months of age. The largest acceptable interocular acuity difference for clinical purposes was 0.10 logMAR. CONCLUSIONS: Age norms for grating acuity along with interocular acuity differences were determined using the sweep-VEP technique. These norms should be incorporated in clinical practice for precise diagnosis of visual status in infants and preverbal children.

OBJETIVOS: Propor valores normativos de acuidade visual de grades e sua respectiva diferença interocular medidas pelo potencial visual evocado de varredura nos primeiros três anos de vida. MÉTODOS: Foram avaliadas 67 crianças sadias, sem doenças oculares, que tiveram a acuidade visual medida pelos potenciais evocados visuais de varredura. RESULTADOS: A acuidade visual média variou de 0,80 logMAR (equivalente de Snellen de 20/125) no primeiro mês de vida a 0,06 logMAR (equivalente de Snellen de 20/20) aos 36 meses. Os limites normais inferiores (percentil 95 por cento) variaram de 0,95 logMAR (20/180) a 0,12 logMAR (20/25) com progressão de aproximadamente 3 oitavas nos primeiros 36 meses de vida. A diferença interocular máxima aceitável foi de 0,10 logMAR. CONCLUSÕES: Os valores normativos de acuidade visual e de diferença interocular de acuidade foram obtidos pela técnica do potencial visual evocado de varredura. Propõe-se sua adoção na prática clínica para diagnóstico preciso do estado visual de bebês e de crianças pré-verbais.

MRI findings and correlative study of MRI and visual evoked potentials in optic neuritis / 中华放射学杂志

Objective To investigate the effective MRI sequences and describe the correlation between MRI and visual evoked potential(VEP)in diagnosing optic neuritis.Methods One hundred and fifty-four eyes with visual impairment of 98 patients with diagnoses of optic neuritis,papillitis,multiple sclerosis and Devic's disease underwent MRI and VEP examination. The MRI findings were analyzed and correlated with VEP results and clinical presentation by using x2 test,wilcoxon test and Kappa test.Results Out of the 154 sick eyes.56 eyes presented thickened optic nerves.76 eyes had normal diameter of the optic nerve,and 22 eyes had thin optic nerves.A total of 132 optic nerves showed abnormally high signal in STIR sequences.including involvement of intraocular segment in 7,intraorbitsl segment in 135,intracanalicular segment in 109,intracranial segment in 97,optic chiasm in 56,and optic tract in 23.A total of 54 patients underwent postcontrast MRI. Seventy-four optic nerves of 87 eyes showed enhancement.Among the 196 eyes of 98 patients,132 eyes presented visual impairment and simultaneous abnormal MR signal of the optic nerve.and 26 eyes had both normal vision and normal MR signal of optic nerve.The consistency of MRI findings and vision status was 80.61%(Kappa=0.453,P＜0.01).Among the 175 eyes with VEP results.129 eyes had visual loss with simultaneous VEP abnormalities,and 30 eyes had both normal vision and normal VEP results.The consistency of VEP and vision status was 90.86%(Kappa=0.731,P＜0.01).Among the 175 eyes with VEP results,117 eyes had abnormal MR signal of the optic nerve and simultaneous abnormal VEP,and 24 eyes had both normal MR signal of the optic nerve and normal VEP.The consistency of MRI findings and VEP was 80.57%(Kappa=0.460,P＜0.01).Conclusion STIR sequence and gadolinium-enhanced T1-weighted MR sequence combined with fatsuppression are helpful in diagnosis of optic neuritis.VEP is helpful in diagnosing optic neuritis and in finding subclinical visual problem.The MRI combined with VEP could improve the diagnostic accuracy of optic neuritis.

The effect of electrode positions on multifocal visual evoked potential / 中华眼底病杂志

Objective To compare the effect of electrode positions o n multifocal visual evoked potential(mf-VEP). Methods Ten healt hy individuals were tested with RETIscan multifocal VEP system 3.20, each indiv idual was tested with four electrode positions: the active and reference electro de were placed 2.0 cm above and below the inion in Ch1;3.0 cm above and 4.5 cm below the inion in Ch2;2.0 cm on both right and left side of the inion in C h3 and 4.0 cm on both right and left side of the inion in Ch4. The summed ampli tudes of hemifield mf-VEP were analyzed and compared according to different ele ctrode positions. Results The difference among summed amplitud es of the upper or lower hemifield mf-VEP recorded with Ch1、Ch2、Ch3 and Ch4 w as statistically significant;and the difference between Ch2 and the other chann els was statistically significant too. The difference among summed amplitudes of the horizontal sites whose amplitudes were small when recorded with Ch2 and sum med amplitudes of the corresponding sites recorded with Ch3 and Ch4 were statist ically significant;and the difference between Ch4 and the other channels was st atistically significant too. Conclusions compared to Ch1、Ch3 and Ch4, Ch2 can make a better recording of mf-VEP. As for some sites, especi ally those along horizontal line, horizontal electrodes could improve the amplit udes of mf-VEP recorded with vertical electrodes,and Ch4 could do better to im prove the mf-VEP recorded with Ch2 than Ch3.

The characteristics of multifocal visual evoked potential in healthy individuals / 中华眼底病杂志

Objective To investigate the characteristics of multifocal visual evoked potential (mf-VEP) in healthy individuals, and provide normal reference values for its clinical application. Methods The mf-VEP of 37 healthy individuals (70 eyes) were examined by VERIS Science TM 4.0. The visual stimulus was a dart board with patterns consisted of 60 patches spanning a 25? visual field. The length of m-sequence was 2 14-1. The results were recorded by bipolar occipital straddle. The signal was amplified 100 K and was put through a band-pass filter between 3 and 100 Hz. The first slice of the second order kernel was analyzed by VERIS software. The summed responses of fields with different stimulus were analyzed and compared according to different ages, genders and eyes. Results The latencies and response densities of amplitude had statistically significant differences both in dimidiate and quartered field(P 0.05). Conclusions The mf-VEP of healthy individuals can reflect the VEP at different field locations objectively with its specific physiological characteristics, which may provide normal reference values for its clinical application.