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)

[Research progression of visual evoked potential in glaucomatous visual function evaluation].

Visual evoked potential (VEP) is often used for the objective evaluation for impairment of visual function. Although these VEP-related tests have good results in the assessment of glaucoma, their application as routine tests in the clinical diagnosis of glaucoma is limited due to the time consumption and easy interference by the environment and the reliance on the experience of the doctors. However, several new VEP detection modes have emerged in the past decade, such as short-duration transient VEP and isolated check VEP. Preliminary studies have shown that both of them have good diagnostic ability in glaucoma, and more studies on the clinical application of these latest technologies are conducive to further understanding of their value in the visual function evaluation and follow-up of glaucoma. (Chin J Ophthalmol, 2020, 56: 61-65).

[Electrophysiology and early glaucoma diagnosis].

Glaucoma can lead to irreversible visual impairment. The pathogenesis of glaucoma is complicated and it is difficult to diagnose early. As an objective and functional examination tool, visual electrophysiology has its own advantages to detect early glaucomatous damage. It can indicate early functional degeneration of retinal ganglion cells and can direct doctors to diagnose and give treatment to glaucoma patients. It has been proved that the pattern electroretinogram, photopic negative response and multifocal electroretinogram can provide most of the information in the early diagnosis of glaucoma. This article overviews the latest application progress of these three visual electrophysiological techniques.(Chin J Ophthalmol, 2018, 54:868-872).

Optic nerve Schwannoma: Neurofibromatosus Type-1? A case report.

Optic nerve Schwannoma is a very rare tumour described in literature. The rarity of this tumour is due to the fact that the optic nerve is myelinated by oligodendrocytes. We present a case of an ancient optic nerve schwannoma in a 16 year old girl who presented to the clinic with right sided proptosis and bilateral loss of vision. She underwent complete excision of the tumour via a craniotomy and histopathology was confirmatory. The various theories explaining the origin of this tumour are discussed along with surgical nuances of removing this tumour. The importance of taking every precaution to preserve vision and avoiding imaging confusion in patients with von Recklinghausen syndrome is also discussed. Only 6 cases of optic nerve schwannomas are described in literature while none have been described in a patient with NF 1.

[Contrast Visual Evoked Potentials under Pattern Stimulus in Ocular Trauma].

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.

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.

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.

The beneficial effects of sounds on attentional blink performance: An ERP study.

Auditory information can affect the processing of visual information. The present study used event-related potentials (ERPs) to characterize the temporal dynamics of this interaction in a rapid serial visual presentation (RSVP) task that created an attentional blink (AB), that is, a profound deficit in detecting or identifying the second of two visual targets embedded in an RSVP stream. When a sound preceded the second target, T2, by 250ms or was played simultaneously with T2, T2 identification accuracy increased to a comparable degree. Sound-related modulations of the visual response to T2 emerged from around 140ms when the sound preceded T2, and from around 100ms when the sound was played simultaneously with T2. Timing and topography of this earliest modulation indicated that it is not related to early sensory areas, but suggest an attentional filter mechanism. Subsequent modulations are compatible with an improvement of early visual processing of T2 and of processes related to target selection both when the sound precedes and when it coincides with T2. For the latter condition our results also indicated processes related to a convergence of stimulus-driven and goal-directed attention. We also observed some overlap between neural correlates of sound-related modulations of the visual response and of correct vs. incorrect performance. Thus, external task manipulations and internal factors contributing to performance in the AB may rely on overlapping though not identical mechanisms.

Visual-evoked potentials in patients with brain circulatory problems.

PURPOSE: The aim of this study was to find out if local brain circulatory problems may influence visual-evoked potentials (VEP). PATIENTS AND METHODS: Thirty-eight patients were divided into the following groups: (I) those with hemianopsia or quadrantanopsia and hemiparesis after brain stroke; (II) those with hemianopsia or quadrantanopsia without paresis after brain stroke; and (III) those with amaurosis fugax. The control group consisted of 38 patients. The VEP pattern (PVEP) and flash VEP (FVEP) were examined monocularly using two electrodes placed at O1 and O2. Latency and amplitude of the N75, P100 and N2, P2 waves were measured. The Newman-Keuls test was used for statistical analysis. RESULTS: In PVEP, no differences between the groups were observed. In FVEP, the mean P2 latency was significantly longer in group I than in group III, and the P2 amplitude was significantly lower in all examined groups when compared with the control group. PVEP and FVEP revealed differences in P latency over 3 ms between brain hemispheres and differences in P amplitude over 30% in all examined groups. In the control group, there were no differences in latency between brain hemispheres and only a small difference in amplitude. CONCLUSION: Local brain circulatory problems that may lead to brain ischemia cause differences in VEP amplitude and latency between brain hemispheres. Changes in VEPs observed in patients with amaurosis fugax may be considered the result of recurrent brain ischemia.

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.

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.

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.

Predicting multiple sclerosis following isolated optic neuritis in children.

BACKGROUND AND PURPOSE: Isolated optic neuritis (ON) is frequently the initial symptom of multiple sclerosis (MS). The aim of our study was to investigate the risk of conversion to MS in children following isolated ON and to evaluate the performance of current diagnostic methods such as cranial magnetic resonance imaging (cMRI), visual evoked potentials (VEPs) and oligoclonal bands in spinal fluid (OCB) as predictive factors for MS development. METHODS: Medical records of 159 patients presenting with acute ON between 2000 and 2010 at the Department of Pediatrics, University of Erlangen, were screened; 34 patients with isolated ON were identified. Progression to MS was defined according to the revised McDonald criteria 2005. Age, sex, VEPs, ON type, cMRI, OCB and visual recovery were assessed as predictors of progression to MS using simple logistic regressions. A multiple logistic regression model included variables found to be significant in univariate analyses. RESULTS: Abnormal cMRI was associated with an increase in the odds of MS development (odds ratio 20.57; 95% CI 2.16-196.10, P < 0.001), as was positive OCB (odds ratio 12.0; 95% CI 1.29-111.32, P = 0.001). However, only cMRI remained statistically significant in multiple regressions. CONCLUSIONS: Multiple sclerosis-like cMRI lesions and OCB are suitable for assessing the risk of progression to MS following isolated ON, as children with both cMRI abnormalities and positive OCB at onset of ON are at high risk of developing MS.

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.