Objective To observe the changes of amplitude and latency of mini visual evoked optential (mini VEP) examinations in infants at different age.Methods A total of 84 healthy infants and adults (168 eyes) were randomly selected to underwent mini VEP. According to the age, all the individuals were divided into seven groups: A, 0-3 months; B, 4-6 months; C: 7-12 months; D: 1-3 years; E: 4-6 years; F: 7-12 years; G: adults (control). There were 12 individuals (24 eyes) in each group. By using the stimulater of mini VEP, the flash VEP was performed and the changes of amplitude and latency of P100 wave were recorded and analyzed.Results The average value of amplitude in group A was（7.39plusmn;1.79）mu;V which was the lowest, and the average latency was （137.45plusmn;7.64）ms which was the largest.At the same time, the average amplitude of P100 increased from group A to E (F=359.56); the average latency decreased from Group A to D（F=326.64）; the difference was significant (P＜0.01). The amplitude in group E, F, and G was high and no significant difference was found (F=2.39，P＞0.05);the latency in group D,E,F,and G was short with no significant difference (F=2.64，P＞0.05）.Conclusions With the growth of the infants' age, the amplitude of miniVEP increases and latency decreases; moreover, the latency reaches the normal adult level in advance of the amplitude of miniVEP.
Objective To observe the results of multifocal visual evoked potential (mfVEP) examination in patients with anterior ischemic optic neuropathy (AION) before and ater treatment, and to probe its clinical significance. Methods A total of 90 patients (90 eyes) with AION were examined by mfVEP; the secondorder reaction of mfVEP was analyzed.The reaction was divided into upper and lower hemi field of visual field, or 1/4 quadrant visual field (superior nasal, inferior nasal, superior temporal, and inferior temporal). The sum of waves of each response was analyzed and the results in various regions were compared.The features of wave configuration was compared between the AION eyes and the contralateral eye, and between the AION eyes before and after treatment.Results The amplitude and latency of P-wave of mfVEP was 0.198plusmn;0.033 and 100.197plusmn;7.354 respectively in AION eyes before treatment, and was 0.271plusmn;0.024 and 98.567plusmn;6.794 in the contralateral eyes; the difference was significant (t=16.556,18.330; Plt;0.01). The amplitude and latency of P-wave of mfVEP was 0.229plusmn;0.016 and 100.104plusmn;10.603 respectively in AION eyes after treatment, which differed much from that before the treatment (t=13.649, 8.858; Plt;0.01) and also from that of the contralateral eyes (t=13.649，8.858；P＜0.01). ConclusionsThe amplitude and latency of P-wave of mfVEP may accurately reflect the recovery of local optic nerve damage in AION eyes before and after treatment with good repeatability. AION can be used as a new method for AION diagnosis and detection of the prognosis.
Objective To compare the effect of electrode positions on multifocal visual evoked potential(mf-VEP). Methods Ten healthy individuals were tested with RETIscan multifocal VEP system 3.20, each individual was tested with four electrode positions: the active and reference electrode 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 Ch3 and 4.0 cm on both right and left side of the inion in Ch4. The summed amplitudes of hemifield mf-VEP were analyzed and compared according to different electrode positions. Results The difference among summed amplitudes of the upper or lower hemifield mf-VEP recorded with Ch1、Ch2、Ch3 and Ch4 was statistically significant；and the difference between Ch2 and the other channels was statistically significant too. The difference among summed amplitudes of the horizontal sites whose amplitudes were small when recorded with Ch2 and summed amplitudes of the corresponding sites recorded with Ch3 and Ch4 were statistically significant；and the difference between Ch4 and the other channels was statistically significant too. Conclusions compared to Ch1、Ch3 and Ch4, Ch2 can make a better recording of mf-VEP. As for some sites, especially those along horizontal line, horizontal electrodes could improve the amplitudes of mf-VEP recorded with vertical electrodes，and Ch4 could do better to improve the mf-VEP recorded with Ch2 than Ch3. (Chin J Ocul Fundus Dis，2004，20：346-348)
Objective To observe the content of thromboxane (TXA2 ) and prostacyclin (PGI2) in optic nerves after forehead impact injury.Methods The right forehead zones of 32 rabbits were struck by biology impact machine. Tweenty-four rabbits that had afferent papillary defect after injury were chosen, and randomly divided into four groups: 1 day, 2, 4, and 7 days group. Right eyes were in the experimental group and left eyes were in the control group. Flash visual evoked potentials were examined before and after the traumatic injury. The rabbits ′eyes were removed, the optic nerves were pathologically examined, and the content of TXB2 and 6-Keto-PGF1αwhich were the products of TXA2 and PGI2 were assayed 1, 2, 4, and 7 days after traumatic injury respectively.Results Histopath ological examination revealed the findings of injuries of optic nerves of all the 24 rabbits. The latency of wave P1 was significantly delayed after traum atic injury (Plt;0.01), and amplitude of wave P1 was significantly decreased after traumatic injury (Plt;0.01). The content of TXB2 ［(172.35±26.52) pg/mg ］and 6-Keto-PGF1α［(161.78±24.83) pg/mg］were significantly higher in the injured optic nerves than in the uninjured ones 1 day after the traumatic injury (Plt;0.01). The rate of TXB2 /6-Keto-PGF1α (1.077±0.18) was significantly increased compared to the control group (Plt;0.05), and lasted to the 7th day.Conclusions The content of TXA2 and PGI2 significantly increases and the ratio of them is lopsided after forehead impact injury in rabbits. (Chin J Ocul Fundus Dis，2003，19：49-51)
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 ScienceTM4.0. The visual stimulus was adart board with patterns consisted of 60 patches spanning a 25°visual field. The length of m-sequence was 214-1. 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 a nalyzed 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（Plt;0.05）. The latencies in ≥50 year group were much more delayed in some sectors of the visual field than those in lt; 50 year group（Plt;0.05）. The latencies of women were shorter than those of men（Plt;0.05）. There was no obvious difference of latencies and response densities of amplitude in each field sectors between both eyes（Pgt;0.05）. Conclusions The mf-VEP of healthy individuals can reflect the VEP at different field ocations objectively with its specific physiological characteristics, which may provide normal reference values for its clinical application.(Chin J Ocul Fundus Dis，2003，19：269-332)
Objective To investigate the characteristic of the multifocal visual evoked potentials(MVEP)and the visual function across the visual field in anisometropic amblyopes and isometropic amblyopes. Methods MVEP from 32 anisometropic amblyopic eyes and 31 control eyes were tested. Results In anisometropic amblyopic eyes,the latencies of MVEP were significantly prolonged．The amplitudes of MVEP were significantly attenuated in the central region of the visual field,and these phenomena gradually reduced with the increase of the eccentricity． Conclusion The visual function of anisometropic amblyopic eyes is reduced more significantly in the central region than in the peripheral region of the visual field. (Chin J Ocul Fundus Dis,20000,16:27-29)
Objective To observe the functional state of the optic nerve and discover the injury of visual pathway function in time under general ane sthesia. The flash visual evoked potential (F-VEP) was used to monitor visual function during orbital surgery. Methods A total of 252 out of 282 patients undergoing orbital surgery under general anesthesia were successfully monitored by F-VEP during the surgery. All patients were monitored by this method under the following conditions:consious state before operation, under general anaesthesia, during and after dissection of orbital tumor and at the end of operation. Results ①There was no significant difference of wave amplitude and latency under general anesthesia and consciousness condition. ②The amplitude and latency of F-VEP were normal in the orbital surgery withou toptic nerve injury. ③Pulling and oppression of optic nerve could cause temporary wave loss, but the wave recovered after removal of the pull and oppression. ④ The wave loss of F-VEP would occur immedicately when optic nerve was severe injured and its blood supply was deficient. Since the application of the visual function monitoring, 24 cases were treated in time during disturbance of visual function and no patient has unexpected visual loss during orbital surgery. Conclusion The intraoperative monitoring of F-VEP during orbital surgery can decrease the proportion of permanent visual loss caused by orbit al surgery, and help the surgical procedures go to function-anatomy stage from experience-anatomy stage. (Chin J Ocul Fundus Dis, 2001,17:260-263)
purpose To study the visual electrophysiological changes in patients with chronic glomerulonephritis. Methods The visual evoked potentials(VEP) and electroretinogram(ERG) of 26 subjects with chronic glomerulonephritis in 51 eyes were recorded. Results Ours studies showed the patients with chronic glomerulonephritis had pathologic visual electrophysiologic abnormalities.The N 75 peak latency,b wave peak latency O 1 peak latency and total amplitude of OPs in chronic glomerulonephritis patients without fundus sign showed remarkable difference. Conclusion These changes suggested visual electrophysiological examination may be valuable in early diagnosis of retinal disfunction in patients with chronic glomerulonephritis. (Chin J Ocul Fundus Dis,1998,14:162-164)
Purpose To investigate the influence of ametropia on stereopsis and its mechanism by using the disparity evoked potential testing. Methods A new set of static random dot stereograms was utilized as a stimulation to elicit the disparity evoked potentials in 21 ametropes and 40 stereo normal subjects. Rezults The P250 wave,which was related to stereoscopic stimulation in ametropes,was recorded in both the ametropes and emetropic stereo normal persons in this series,and the characteristic changes of P250 wave with increasing visual disparity in ametropes were similar to those in normal subjects.The differences of mean amplitudes and latencies of P250 waves between myopes and hyperopes were not significant. Conclusion Ametropia in full correction dose not significanly affect the function of stereopsis. (Chin J Ocul Fundus Dis,1998,14:225-227)
ObjectiveTo investigate the value of pattern reversal visual evoked potential (PRVEP) and sweep pattern visual evoked potential (SPVEP) in evaluating the visual function of patients with central serous chorioretinopathy (CSC).MethodsA retrospective clinical trial. A total of 38 monocular CSC patients were enrolled from March 2016 to December2018 in Heping Hospital Affiliated Changzhi Medical College. There were 34 males and 4 females with the mean age of 40.0±5.2 years. All patients undergo PRVEP detection in both the acute phase (disease course ≤ 3 months) and the clinical cure phase (disease course ≤ 6 months) using the German Roland electrophysiological RETIport system.The stimulation pattern adopted a checkerboard with 1.00° and 0.25° stimulation angles. The P100 peak amplitude and peak time were observed. SPVEP inspection equipment and methods were the same as PRVEP, and the spatial frequency was 1, 2, 4, 6, 8, 12, 16, 22 cpd. The difference between SPVEP vision and subjective vision were compared. The PRVEP peak amplitude, peak time and SPVEP amplitude and phase of the affected eye and the contralateral eye were compared by paired t test; the subjective vision and SPVEP visual acuity of the affected eye and the contralateral eye were compared by Wilcoxon paired rank test; Pearson product-moment correlation analysis was performed on SPVEP vision.ResultsIn the acute phase, the peak amplitude of P100 in the affected eye was lower than that in the contralateral eye (t=30.26, 13.59), and the peak time was prolonged (t=－19.89, －29.41). The difference was statistically significant (P＜0.01); in clinically cured period, the P100 peak amplitude (t=1.49, －0.57) and peak time (t=－1.22, －1.84) of the affected eye and the contralateral eye showed no significant difference (P＞0.05). In the acute phase, the difference in SPVEP amplitude between the affected eye and the contralateral eye with different spatial frequencies was statistically significant (P＜0.01); the phase of the affected eye and the contralateral eye were compared about the spatial frequency 1, 2, 4, 6, 8, 12 cpd, the difference was statistically significant (P＜0.01). During the clinical cure period, the spatial frequency of 6, 8, 12, 16 cpd, the SPVEP amplitude of the affected eye and the contralateral eye, the difference was statistically significant (P＜0.01); on the spatial frequency of 6, 8, 12 cpd, the phase of SPVEP was compared between the affected eye and the contralateral eye, the difference was statistically significant (P＜0.01). During the acute phase and the clinical cure phase, the SPVEP visual acuity of the affected eye was lower than that of the contralateral eye, and the difference was statistically significant (P＜0.01); during the acute phase and clinical cure phase, the SPVEP visual acuity of the affected eye and the contralateral eye were lower than the subjective vision. The difference was statistically significant (acute phase: Z =－5.38, －3.00; P＜0.001, 0.003; clinical cure phase: Z=－5.36, －5.38; P＜0.001,＜0.001). In the acute phase, the subjective visual acuity of the affected eye was positively correlated with SPVEP visual acuity (r=0.847, P＜0.001).ConclusionsPRVEP and SPVEP are useful for objectively assessing the visual function of the patients with CSC. Especially, the slight and potential visual impairment in CSC can been detected by SPVEP.