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Purpose: There are no effective treatments currently available for optic nerve transection injuries. Stem cell therapy represents a feasible future treatment option. This study investigated the therapeutic potential of human umbilical cord–derived mesenchymal stem cell (hUC?MSC) transplantation in rats with optic nerve injury. Methods: Sprague–Dawley (SD) rats were divided into three groups: a no?treatment control group (n = 6), balanced salt solution (BSS) treatment group (n = 6), and hUC?MSCs treatment group (n = 6). Visual functions were assessed by flash visual evoked potential (fVEP) at baseline, Week 3, and Week 6 after optic nerve crush injury. Right eyes were enucleated after 6 weeks for histology. Results: The fVEP showed shortened latency delay and increased amplitude in the hUC?MSCs treated group compared with control and BSS groups. Higher cellular density was detected in the hUC?MSC treated group compared with the BSS and control groups. Co?localized expression of STEM 121 and anti?S100B antibody was observed in areas of higher nuclear density, both in the central and peripheral regions. Conclusion: Peribulbar transplantation of hUC?MSCs demonstrated cellular integration that can potentially preserve the optic nerve function with a significant shorter latency delay in fVEP and higher nuclear density on histology, and immunohistochemical studies observed cell migration particularly to the peripheral regions of the optic nerve.
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@#AIM: To detect the visual dysfunction, and investigate the changes of Tau and its phosphorylated Ser396/Ser404 forms in retinas and optic nerves in traumatic optic neuropathy(TON)model rats by using FVEP technique.<p>METHODS: Totally 30 SD rats were conducted FVEP electrode implantation. One week later, all rates were implemented TON operation with the optic nerve of left eye crushed and the optic nerve of right eye exposed(sham-operated). FVEP detections were performed respectively in these TON model rats at 1, 3, 7, 14, and 28d post crush, with 5 rats tested at each time point. After FVEP tests were taken, rats were sacrificed and then retinas and optic nerves of left eyes were separated for detecting the expression levels of Tau and pTau-Ser396/404 by Western Blot.<p>RESULTS: Typical FVEP waves were observed in the sham-operated eyes. Compared to the sham group, the N2 waves were significantly delayed and the amplitude of N2-P2 were greatly reduced at each time point in the operation eyes. However, the differences of N2 wave and the amplitude reduction of N2-P2 were not significant at each time point after crush. The contents of total Tau protein in retinas of TON rats sharply decreased at 1d post crush, briefly recovered at 7d post crush, and remained a slightly lower level than normal condition till 28d. The changes of pTau-Ser396/404 were consistent with the changes of total Tau in retains and the Ser396 was the main phosphorylation site. However, the total Tau contents in optic nerves of TON rats increased gradually, and peaked at the 14d post crush and remained till 28d. The changes of pTau-Ser396/404 were similar to the changes of total Tau in optic nerves, which peaked at 7d post crush. However, Ser404 was the main phosphorylation site of Tau in optic nerves.<p>CONCLUSION: The related indexes of N2 and P2 waves in FVEP can be used to detect the visual dysfunction in TON rats. After TON, the content changes of total Tau in retinas and optic nerves were much different while the changes of pTau-Ser396/404 followed the alterations of total Tau in the two locations. However, the main phosphorylation site of Tau was differnet according to the locations.
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@#AIM: To compare the pre-and postoperation results of flash visual evoked potential(FVEP)and pattern visual evoked potential(PVEP)and to discuss the significance of FVEP and PVEP examinations in assessing postoperative visual acuity in senile cataract patients. <p>METHODS: During the period of June 2015 to May 2016, 68 cases of senile cataract patients(79 eyes)were treated in our hospital. This research analyzed the changes of pre- and postoperative FVEP and PVEP results and compared the preoperative FVEP, PVEP, FVEP combined with PVEP results with the postoperative best corrected visual acuity(BCVA). <p>RESULTS: There was no statistically significant difference in the incubation time of P2 wave and the amplitude of N2-P2 wave of FVEP pre-and postoperative examination(<i>t</i>=0.448, -0.492; <i>P</i>>0.05), there was statistically significant difference in the incubation time of P100 wave and the amplitude of N75-P100 wave of PVEP pre-and postoperative examination(<i>t</i>=2.505, -5.462; <i>P</i><0.05).The incubation time of P2 and P100 wave before operation were significantly negatively correlated with the postoperative BCVA(<i>r</i>=-0.694, -0.402; <i>P</i><0.05). The amplitude of N2-P2 wave before operation was significantly positively correlated with the postoperative BCVA(<i>r</i>=0.607,<i>P</i><0.01). There was no significant correlation between the amplitude of N75-P100 wave before operation and the postoperative BCVA(<i>r</i>=0.237,<i>P</i>>0.05).Consistent rate of FVEP examination was 83.54%, that of PVEP was 66.67%, the difference was statistically significant(<i>χ</i><sup>2</sup>=5.11,<i>P</i><0.05).Consistent rate of FVEP combined with PVEP examination was 90.74%, that of PVEP was 66.67%, the difference was statistically significant(<i>χ</i><sup>2</sup>=9.34,<i>P</i><0.01). <p>CONCLUSION: By comparision, FVEP is better and more accurate than PVEP in predicting the postoperative visual acuity. Preoperative FVEP together with PVEP examinations can effectively and objectively assess postoperative visual function recovery of senile cataract patients whose corrected visual acuity of the proposed surgical eyes before operation is ≥0.1.
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Background Optic nerve crush (ONC) model is an available tool in the basic research on the mechanism and treatment of optic nerve injury.The opening optic nerves sheath crushing and via bulbar conjunctiva lateral canthus optic nerves crushing are frequently used ONC modeling methods.However,the comparison between these models is not elaborated.Objective This study was to compare the outcomes between opening sheath ONC model and via bulbar conjunctiva lateral canthus ONC model.Methods Twenty-four male SD rats were randomized into four groups.ONC models were established via superorbital rim opening sheath to crushing optic nerve for 20 seconds in the opening sheath ONC group,or via bulbar conjunctiva lateral canthus cutting to crush optic nerve for different time in the via bulbar conjunctiva ONC 20-second,40-second and 60-second groups,respectively.All models were monocular created in the rats,and the fellow eyes served as controls.In 14 days after modeling,flash visual evoked potential (F-VEP) were recorded,optic nerve and retinal sections were prepared in the rats.The histopathology of the samples was examined by hematoxylin and eosin staining.The expression of Brn-3α in the retinal ganglion cells (RGCs) was detected by immunofluorescence technique and the number of Brn-3α+ RGCs was counted.The modeling procedure and outcomes were compared between the two approaches.Results The latencies of P1 waves were significantly extended in the opening sheath ONC group,via bulbar conjunctiva ONC 20-second,40-second and 60-second groups in comparison with the corresponding control eyes (t =-11.64,-8.04,-6.50,-10.84,all at P＜0.01).The P1 latencies were longer in the opening sheath ONC group than those in the via bulbar conjunctiva ONC 20-second,40-second and 60-second groups (P =0.01,0.02,0.05),but no significant differences were found in the amplitudes of P1 waves between model eyes and corresponding control eyes (all at P＞0.05).The Brn-3α+ RGCs numbers were evidently decreased in the model eyes in comparison with the fellow control eyes.The Brn-3 α + RGCs numbers were (13.60 ± 2.14),(18.74 ± 3.61),(15.84 ± 2.31) and (14.58 ± 3.23)/field in the opening sheath ONC group,via bulbar conjunctiva ONC 20-second,40-second and 60-second groups,which reduced to 47.49％,67.70％,56.69％ and 50.17％ of the fellow eyes,respectively.No significant differences were seen in the Brn-3α+ RGC numbers between the opening sheath ONC group and via bulbar conjunctiva ONC 40-second or 60-second groups (both at P＞0.05).The disorder of glial cell arrangement,vacuolization of the cell matrix and infiltration of inflammatory cells were displayed in various model groups,with the prominent findings in the opening sheath ONC group.Conclusions Compared with the via bulbar conjunctiva ONC models,the morphological and functional damage of optic nerve is more obvious,and the survival rate of RGCs is lower in the opening sheath ONC models.
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Visual Evoked Potentials (VEPs) are evoked potentials generated in response to visual stimuli. The flash VEP (FVEP) is used less frequently than pattern-reversal VEP (PR-VEP) because; it shows great variations in both latency and amplitude in normal subjects. The advantage of FVEP is its feasibility in non-cooperative subjects, which circumvents the major limitation of PR-VEP. The present study was undertaken to assess the effect of change of color of flashlight on variability of FVEP latencies. Healthy subjects in the age group of 18-30 years underwent the standard stimulus using white light, followed by altered stimuli done with red and blue light. 2 trials were given for each eye, for each type of stimulus. The same set of studies was repeated at the same clock time the following day. The inter-individual and intra-individual variability in the peak latency of P2 and N2 waveforms was assessed using coefficient of variation (COV). Both inter-individual and intra-individual variability was less when monochromatic light was used. Between red and blue FVEP, inter-individual variability was less in blue FVEP and the results of intra-individual variability was inconclusive. Monochromatic stimulation preferably with blue light reduced both inter-individual and intra-individual variability seen in latency of P2 and N2 waveforms in FVEP and hence recommended in preference to standard white stimulus for FVEP recording.
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Objective To determine whether or not 810 nm low power Ga-Al-As laser treatment can stimulate the regeneration of damaged optic nerves by measuring the expression of growth associated protein 43 ( GAP-43 )and flash-visual evoked potential (F-VEP). Methods Eighty-eight Wistar rats weighing (180-220) g were randomly divided into a laser therapy group with 40 rats,an injury group with 32 rats,and a normal control group with 16 rats.Each group was subdivided into 1st,3rd,6th and 9th week subgroups.A standardized crushing of the optic nerve was applied to make the model.After this,the laser therapy group was treated for 3 minutes daily at 60 mW applied transcutaneously to a 5 mm diameter spot on the injured optic nerve.The injury and normal control groups received the same treatment with no laser output.The expression of GAP-43 was detected by immunohistochemistry and RT-PCR after 1,3,6 and 9 weeks of treatment.F-VEP was measured pre-injury,immediately after injury and 1,3,6 and 9 weeks post injury. Results After the optic nerve was injured,obvious changes in F-VEP were detected,including significantly prolonged latencies of N1,P1 and N2 waves.The latency increased immediately after the optic nerve injured,and then recovered,but after 1 and 3 weeks the latency was still prolonged.There was significant recovery from the 3rd to the 9th week.In the laser therapy group,the peak latencies of the N1,P1 and N2 waves were also prolonged,but the changes were less than those in the injury group.Expression of GAP-43 was hardly detectable in normal retinas and optic nerves.GAP-43 had its highest expression level at 1 week post-injury,and then decreased.At the 1st,3rd and 6th week post-injury,the expression of GAP-43 in the laser therapy group was significantly higher than in the injury group.GAP-43 mRNA content in the retina showed the same tendency as GAP-43 protein. Conclusion A 810 nm low power Ga-Al-As laser can promote neural repair and axonal regeneration after optic nerve injury.
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@#ObjectiveTo explore the relationship between flash visual evoked potentials (fVEP) and intracranial pressure (ICP), and the effect of fVEP on monitoring ICP treatment.MethodsICPs of 37 patients with large area cerebral infarction and intracranial hypertension were measured before and at 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after mannitol treatment.ResultsThe mannitol effect to cure the large area cerebral was not well.ConclusionfVEP can monitor ICP exactly and harmless, and has importance value to instruct therapy of ICP in clinic.
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Objective To investigate the effects of chondroitin sulfate proteoglycans (CSPGs) degradation induced by chondroitinase ABC (ChABC) on the rat flash visual evoked potential (F-VEP) around the end of the critical period of visual development.Methods A total of 30 Long Evans rats were randomly divided into 3 groups according to their age of 14,21 and 35 d.Then in each group,5 animals served as CSPGs degradation model induced by ChABC microinjection into 5 sites of the rat cortex [750 nL (48 U/ml) for 1 site,for 2 times at a 3-day interval],and the other 5 rats served as normal control and received normal saline microinjection.Immunofluorescence microscopy and laser scanning confocal microscopy were used to determine the establishment of animal model.F-VEPs were evaluated in 7 d after first microinjection.Results In the normal rats,the latency of F-VEP main wave became shorter with the increase of their age,the number was [(63.5?10.1),(50.8?6.4),(44.9?6.3) ms,P
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Objective To research the relationship between flash visual evoked potentials (fVEP)and intracranial pressure (ICP),to evaluate the usefulness of baseline fVEP testing in the diagnosis of increased ICP Methods 22 normal individuals,44 increased intracranial pressure patients and other 35 patients which were measured by lumbar puncture were recorded with fVEP The latency of their waves were compared Results A positive correlationship between elevated intracranial pressure and a latency shift of the P 2,N 2,P 3,N 3 wave of the flash evoked potential is demonstrated( P
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Objective To investigate the cerebral regularity of dynamic charge and the correlation with intracranial pressure(ICP),clinical seriousness and prognosis on acute stage of intracerebral hemorrhage(ICH) patients by transcranial Doppler(TCD).Methods 54 patients with first acute supratentorial ICH 24h after onset were studied.All patients were dynamic evaluated by beside TCD on 1st,7th,21st day.The correlation of TCD with ICP,MESSS were studied.Results On the 1st day the TCD abnormity of the acute phase of the ICH occurred mainly in the anterior circulation of cerebrum,in which the cardinal manifestation was high-resistance,low-flow velocity blood waveforms,especially on the bleeding side.Continuous TCD monitoring revealed the low velocity of the cerebral blood flow increased;meanwhile the high value of PI decreased gradually and the TCD monitoring was within the normal range three weeks after the attack.The ICP had negative correlation with the VmMCA,positive correlation with the PI value.MESSS scale had negative correlation with the VmMCA,positive correlation with the PI value.Conclusions The TCD examination can be used to monitor the cerebral hemodynamics of the patients suffering from intracerebral hemorrhage.The combination of fVEP and TCD facilitate the evaluation of the dynamic changes of ICP so as to instruct lowering the ICP.