Objective Assessment of Visual Field Defects Caused by Optic Chiasm and Its Posterior Visual Pathway Injury / 法医学杂志

OBJECTIVES@#To investigate the characteristics and objective assessment method of visual field defects caused by optic chiasm and its posterior visual pathway injury.@*METHODS@#Typical cases of visual field defects caused by injuries to the optic chiasm, optic tracts, optic radiations, and visual cortex were selected. Visual field examinations, visual evoked potential (VEP) and multifocal visual evolved potential (mfVEP) measurements, craniocerebral CT/MRI, and retinal optical coherence tomography (OCT) were performed, respectively, and the aforementioned visual electrophysiological and neuroimaging indicators were analyzed comprehensively.@*RESULTS@#The electrophysiological manifestations of visual field defects caused by optic chiasm injuries were bitemporal hemianopsia mfVEP abnormalities. The visual field defects caused by optic tract, optic radiation, and visual cortex injuries were all manifested homonymous hemianopsia mfVEP abnormalities contralateral to the lesion. Mild relative afferent pupil disorder (RAPD) and characteristic optic nerve atrophy were observed in hemianopsia patients with optic tract injuries, but not in patients with optic radiation or visual cortex injuries. Neuroimaging could provide morphological evidence of damages to the optic chiasm and its posterior visual pathway.@*CONCLUSIONS@#Visual field defects caused by optic chiasm, optic tract, optic radiation, and visual cortex injuries have their respective characteristics. The combined application of mfVEP and static visual field measurements, in combination with neuroimaging, can maximize the assessment of the location and degree of visual pathway damage, providing an effective scheme for the identification of such injuries.

Study on the changes of visual function and multifocal visual evoked potential in children with strabismus after intermittent exotropia operation / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the changes of visual function and multifocal visual evoked potential in children with strabismus after intermittent exotropia operation.<p>METHODS: Totally 91 children with intermittent exotropia from January 2014 to December 2017 were enrolled in the study. All children were treated with surgery. The changes of visual function before and after operation were observed, and the level of multifocal visual evoked potential before and after operation were detected. <p>RESULTS: The total effective rate was 88% at one week after operation, 86% at 6mo after operation, the mean preoperative strabismus was-38.12△, and the mean postoperative strabismus was-5.8△. At 6mo after operation, the number of children with simultaneous vision, fusion and distant stereopsis decreased significantly as compared with that before operation(<i>P</i><0.01). The orthopedic rate was 68% at 6mo after operation, and the majority of the patients with all or only one or two grade visual function before the operation were positive, which was significantly higher than that of the patients who lost it after operation(<i>P</i><0.05). From before operation to 6mo after operation, the amplitude response density of the characteristic peak and the latency of the nasal and temporal retinas in the fourth and sixth rings of the children were significantly increased, while the latent period of the inferior retina was significantly decreased(<i>P</i><0.05).<p>CONCLUSION: Intermittent exotropia operation can effectively improve the visual function of children and promote the recovery of eye position in children, and the level of multifocal visual evoked potential in children after operation is also improved to some extent. The clinical effect is outstanding, and it is worth popularizing and applying.

Multifocal visual evoked potential in optic neuritis, ischemic optic neuropathy and compressive optic neuropathy.

Purpose: To investigate the effect of optic neuritis (ON), ischemic optic neuropathy (ION) and compressive optic neuropathy (CON) on multifocal visual evoked potential (mfVEP) amplitudes and latencies, and to compare the parameters among three optic nerve disorders. Materials and Methods: mfVEP was recorded for 71 eyes of controls and 48 eyes of optic nerve disorders with subgroups of optic neuritis (ON, n = 21 eyes), ischemic optic neuropathy (ION, n = 14 eyes), and compressive optic neuropathy (CON, n = 13 eyes). The size of defect in mfVEP amplitude probability plots and relative latency plots were analyzed. The pattern of the defect in amplitude probability plot was classified according to the visual field profile of optic neuritis treatment trail (ONTT). Results: Median of mfVEP amplitude (log SNR) averaged across 60 sectors were reduced in ON (0.17 (0.13‑0.33)), ION (0.14 (0.12‑0.21)) and CON (0.21 (0.14‑0.30)) when compared to controls. The median mfVEP relative latencies compared to controls were significantly prolonged in ON and CON group of 10.53 (2.62‑15.50) ms and 5.73 (2.67‑14.14) ms respectively compared to ION group (2.06 (‑4.09‑13.02)). The common mfVEP amplitude defects observed in probability plots were diffuse pattern in ON, inferior altitudinal defect in ION and temporal hemianopia in CON eyes. Conclusions: Optic nerve disorders cause reduction in mfVEP amplitudes. The extent of delayed latency noted in ischemic optic neuropathy was significantly lesser compared to subjects with optic neuritis and compressive optic neuropathy. mfVEP amplitudes can be used to objectively assess the topography of the visual field defect.

Evaluation of Hemifield Sector Analysis Protocol in Multifocal Visual Evoked Potential Objective Perimetry for the Diagnosis and Early Detection of Glaucomatous Field Defects

PURPOSE: Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. METHODS: Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. RESULTS: Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. CONCLUSIONS: The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss.

Evaluation of Hemifield Sector Analysis Protocol in Multifocal Visual Evoked Potential Objective Perimetry for the Diagnosis and Early Detection of Glaucomatous Field Defects

PURPOSE: Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. METHODS: Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. RESULTS: Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. CONCLUSIONS: The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss.

The Change of Multifocal Visual Evoked Potential in Unilateral Anisometropic Amblyopia before and after Occlusion Treatment

PURPOSE: To evaluate the change in multifocal visual evoked potential (mfVEP) in unilateral anisometropic amblyopia before and after occlusion treatment. METHODS: The mfVEP was performed using RETIscan(R) (Roland,Brandenburg, Germany) for patients with unilateral anisometropic amblyopia before and after occlusion treatment. Amplitude and latency values of mfVEP were analyzed according to the field divided by 6 rings or 4 sectors. RESULTS: The each amplitude of values of all 6 rings were not significantly different before treatment (p = 0.077) in amblyopic eyes. However, the value of ring 1 (p = 0.00) was significantly higher than the value of other rings after treatment. In fellow eyes, the values of ring 1 was consistently significantly higher than the value of other rings before (p = 0.014) and after (p = 0.049) occlusion treatment. Additionally, the amplitudes of ring 1 (p = 0.005) and ring 3 (p = 0.007) were significantly increased in amblyopic eyes after occlusion treatment. In fellow eyes, the values of all rings did not change significantly. The analysis of amplitudes with 4 sectors revealed no significant result. The analysis of latencies with 6 rings and 4 sectors revealed no significant result. CONCLUSIONS: The change in amplitude on the central field (ring 1) in amblyopic eyes can be a useful objective monitoring method observing the improvement progress in visual acuity.

The Change of Multifocal Visual Evoked Potential in Unilateral Anisometropic Amblyopia before and after Occlusion Treatment

PURPOSE: To evaluate the change in multifocal visual evoked potential (mfVEP) in unilateral anisometropic amblyopia before and after occlusion treatment. METHODS: The mfVEP was performed using RETIscan(R) (Roland,Brandenburg, Germany) for patients with unilateral anisometropic amblyopia before and after occlusion treatment. Amplitude and latency values of mfVEP were analyzed according to the field divided by 6 rings or 4 sectors. RESULTS: The each amplitude of values of all 6 rings were not significantly different before treatment (p = 0.077) in amblyopic eyes. However, the value of ring 1 (p = 0.00) was significantly higher than the value of other rings after treatment. In fellow eyes, the values of ring 1 was consistently significantly higher than the value of other rings before (p = 0.014) and after (p = 0.049) occlusion treatment. Additionally, the amplitudes of ring 1 (p = 0.005) and ring 3 (p = 0.007) were significantly increased in amblyopic eyes after occlusion treatment. In fellow eyes, the values of all rings did not change significantly. The analysis of amplitudes with 4 sectors revealed no significant result. The analysis of latencies with 6 rings and 4 sectors revealed no significant result. CONCLUSIONS: The change in amplitude on the central field (ring 1) in amblyopic eyes can be a useful objective monitoring method observing the improvement progress in visual acuity.

Study for Analysis of the Multifocal Visual Evoked Potential

PURPOSE: To introduce the clinical utility of the absolute value of the reconstructed waveform method in the analysis of multifocal visual evoked potential (mfVEP). METHODS: The mfVEP with 4-channel recording was performed using RETIscan(R) on 10 eyes of 10 normal subjects. Amplitudes were obtained from ring-shaped 6 areas and 4 sectors. The best visual evoked potential (VEP) response method and the absolute value of the reconstructed waveform method were compared in terms of analysis of the amplitudes. In order to assess the false positive rate of the examination, stimuli were administered with one-half of the cathode ray tube (CRT) monitor completely covered and the results were compared using 2 methods. RESULTS: The amplitudes in 6 areas and 4 sectors analyzed with the best VEP response method and the absolute value of the reconstructed waveform method showed no statistical difference (p > 0.05). The amplitude in the stimuli-blocked area of the absolute value of the reconstructed waveform method was smaller than that of the best VEP response method (p 0.05). CONCLUSIONS: The absolute value of the reconstructed waveform method has similar reproducibility and lower level of false positives relative to the best VEP response method. Therefore, it can be considered as a useful method in the analysis of the mfVEP.

Study for Analysis of the Multifocal Visual Evoked Potential

PURPOSE: To introduce the clinical utility of the absolute value of the reconstructed waveform method in the analysis of multifocal visual evoked potential (mfVEP). METHODS: The mfVEP with 4-channel recording was performed using RETIscan(R) on 10 eyes of 10 normal subjects. Amplitudes were obtained from ring-shaped 6 areas and 4 sectors. The best visual evoked potential (VEP) response method and the absolute value of the reconstructed waveform method were compared in terms of analysis of the amplitudes. In order to assess the false positive rate of the examination, stimuli were administered with one-half of the cathode ray tube (CRT) monitor completely covered and the results were compared using 2 methods. RESULTS: The amplitudes in 6 areas and 4 sectors analyzed with the best VEP response method and the absolute value of the reconstructed waveform method showed no statistical difference (p > 0.05). The amplitude in the stimuli-blocked area of the absolute value of the reconstructed waveform method was smaller than that of the best VEP response method (p 0.05). CONCLUSIONS: The absolute value of the reconstructed waveform method has similar reproducibility and lower level of false positives relative to the best VEP response method. Therefore, it can be considered as a useful method in the analysis of the mfVEP.

Multifocal Visual Evoked Potential in Normal Subjects

PURPOSE: To introduce the clinical utility of multifocal visual evoked potential (mfVEP) and to assess the waveform from normal Korean subjects. METHODS: mfVEP with 4 channel recording was performed using the RETIscan(R) system (Roland Consult, Wiesbaden, Germany) for 25 eyes of 25 normal subjects. Amplitudes and implicit times were obtained from ring-shaped 6 areas and 4 sectors. To investigate the false-positive ratio of the examination, stimuli were given with one-half of the CRT monitor completely covered and the results were compared. RESULTS: Amplitudes of P1, N2 were larger in the central 10degrees area than other areas (p<0.001). Amplitudes were reduced and implicit times were prolonged on peripheral areas. P1 amplitudes were larger in the inferior field. Waves with large amplitudes by noise were recorded in 13.7% of covered areas. CONCLUSIONS: mfVEP is useful tool to detect local optic nerve damage and rule out the non-organic cause of visual field defect. However, mfVEP results are difficult to interpret due to noise and poor patient cooperation. Standardization of mfVEP is necessary for its application.

Prediction of multifocal visual evoked potential for postoperative visual recovery in cataract patients / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To determine multifocal visual evoked potential (mVEP) in the prediction of postoperative visual acuity in cataract. METHODS: We examined 30 normal eyes as control and 60 eyes of 52 cataract patients, senile cataract in 27 cases 30 eyes, cataract with glaucoma in 25 cases 30 eyes by mVEP examination. All patients underwent phacoemulsifi-cation (Phaco) and intraocular lens (IOL) implantation. After surgery,best corrected visual acuity (BCVA) was examined at 1 week, 1 month, and 3 months respectively.RESULTS: The mean amplitude and latency in mVEP responses between normal control group were 183±11nV, 95±8ms, and in senile cataract group were 177±10nV, 96± 8ms respectively, there were no significant difference between two groups (P>0.05). The mean amplitude and latency of cataract with glaucoma 138±7nV, 99±6ms were significantly different comparing to both control and senile cataract group (P<0.05). After surgery, the am-plitude and latency were 276±11nV and 93±8ms respec-tively, which did not change significantly comparing to the normal eyes (P<0.05), their visual function got no obvious damage and visual recovery were better (BCVA≥0.8). While those with central amplitude 221±6nV and latency 105±7ms that were significantly deviated from control group (P<0.05), and their visual function were seriously damaged and visual recovery were much poorer (BCVA<0.3).CONCLUSION: mVEP waveform might enable us to evaluate objective visual function detection before cataract surgery. A subject with visual function damage, their mVEP responses to stimulation were severely changed when it compared to controls.

Multifocal VEP in patients with optic nerve disease / 国际眼科杂志(Guoji Yanke Zazhi)

· AIM:To determine whether the multifocal visual evoked potential (mfVEP) can be used as a clinical method to assess the patients with optic nerve disease.· METHODS: Fifteen patients with optic nerve disease were examined in this study. All patients underwent visual acuity examination, slit-lamp inspection, ophthalmoscopy, Goldmann perimeter, fundus fiuorescein angiography, visual field and mfVEP. Although these patients with unilateral optic nerve damage,data from both eyes were included in the analysis.· RESULTS:In all patients the visual fields defect was demonstrated on the mfVEP and showed good correspondence in location of the scotoma. However, we also found some slight difference between visual field and mfVEP. In some locations, when the local visual fields were normal, mfVEP showed that its amplitude reduced. In reverse, when the local mfVEP seemed normal, visual field showed abnormity.· CONCLUSION:Multifocal visual evoked potential could be used as a clinical diagnosis option in patients with optic nerve disease. Local monocular damage to the optic nerve can be measured by an interocular comparison of the mfVEP.

The comparison of mfVEP in normal eyes and glaucomatous eyes / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To test the ability of multifocal visual evoked potential (mfVEP) in the detecting of glaucoma by comparing the mfVEP recorded from normal subjects and glaucoma patients.METHODS: The mfVEP of 32 normal eyes (n =21) and of 58 eyes (n =37) with primary glaucoma were recorded with the Vision Monitor electrophysical apparatus by the second kernel analysis and to determine the correlation of the topographic location between them.RESULTS: There were significant variability (the coefficient of variation was 43.05%) in mfVEP RMS amplitude in the normal subjects; The RMS amplitude of eyes with glaucoma were smaller than that of the normal eyes and significantly statistical difference were found in the relatively center (namely the 0° -10° ring zone) and in superior nasal quadrant (P＜0.05) while there were no significantly statistical differences of the latency time between them.CONCLUSION: The normal subjects have large individual variability of mfVEP responses. The RMS amplitude of the mfVEP of glaucomatous eyes descends, especially in center zone and superior nasal quadrant.

Effect of experimental scotoma on multifocal visual evoked potential / 第三军医大学学报

Objective To investigate the influence of experimental scotoma on multifocal visual evoked potential (mf-VEP). Methods The mf-VEP of 10 healthy individuals (20 eyes) was measured with VERIS Science 4.0. Every eye was measured for 3 times. The right eye was measured with full field stimulation and upper hemi-field or lower hemi-field masked. The left eye was measured with full field stimulation and central three-rings area or lower nasal field masked. The first slice responses of the second order in different field were analyzed and compared by VERIS software. Results The mf-VEP in masked area was undetectable or obviously decreased in all subjects. In most unmasked field, the amplitudes of mf-VEP were not changed, except that in some place decreased slightly with statistically significant difference in comparison to the full field stimulation mode. Conclusion mf-VEP is influenced with experimental scotoma. The mf-VEP changes are consistent with the visual field masked.

The symmetry of multifocal visual evoked potential between both eyes in normal subjects / 中华眼底病杂志

ObjectiveTo analyze the symmetry of multifocal visual evoked potential (mfVEP) between both eyes in normal subjects. Methods The monocular mfVEP of both eyes in thirty-six normal subjects (72 eyes) was tested with VERIS Science 4.0. The stimulus was the pattern reversal dart array consisted of 60 sectors each included 16 black-white reverse patterns. The visual stimulation was controlled by the binary pseudo-random m-sequences and subtended approximately 25 degrees. Results There existed no statistically significant difference of P1 latencies and amplitudes between correspondent quadrant visual field of both eyes. The data difference of the ipsilateral quadrant visual fields was greater than those of the correspondent quadrant visual field. The comparison among four quadrant visual fields in right eye or left eye each showed that there was statistically significant difference of P1 latencies between the superionasal quadrant visual field and inferiotemporal or inferionasal quadrant visual fields. Conclusions The symmetry of normal mfVEP is more dominant in retina than that in visual cortex.

Multifocal visual evoked potential in the detection of glaucomatous field defects / 眼科

Objective To evaluate the effect of multifocal visual evoked potential(mfVEP)on the detection of glaucomatous field defects. Design Case-controlled study. Participants 20 healthy individuals and 20 patients with primary glaucoma accepted mfVEP test. Methods 20 healthy individuals and 20 patients with primary glaucoma were tested with RETIscan multifocal VEP System 3.20 and OCTOPUS 101 automated perimetry G2 test program. Amplitudes were measured and interocular response asymmetry coefficient (RAC) was calculated for each site from all participants. The abnormal areas from mfVEP test were compared with field defects from automated perimetry. Main Outcome Measures Amplitude, RAC. Results 90% of suffered eyes showed at least 3 adjacent points had an amplitude decrease or RAC outside 2 standard deviations (SD) from healthy individual database, in which 63% showed at least 3 adjacent points had an amplitude decrease outside 2 SD from normal database while 70% showed at least 3 adjacent points had a RAC outside 2 SD from normal database. 2 patients (2 eyes) had field defects in mfVEP though automated perimetry showed normal field. None of the healthy showd field defects in mfVEP test. Conclusions mfVEP could be used to detect field defects of glaucoma.