Purpose:.To analyze the retinal symmetry of multifocal visual evoked potential (mfVEP) in both eyes of normal subjects. Methods: The monocular mfVEP in both eyes of 36 normal subjects (72 eyes) were tested with VERIS ...Purpose:.To analyze the retinal symmetry of multifocal visual evoked potential (mfVEP) in both eyes of normal subjects. Methods: The monocular mfVEP in both eyes of 36 normal subjects (72 eyes) were tested with VERIS Science 4.0. The stimulus was the pattern reversal dart array consisted of 60 sectors each including 16 black-white reverse patterns. The visual stimulation was controlled by a binary pseudo-random m-sequence and subtended 25 degrees of retinal region. Results: The mfVEP patterns between left and right eyes of each subject were similar, and P1 latency and amplitude in correspondent visual field quadrants between left and right eyes had no significant difference(P>0.05). The latency of superotemporal visual field quadrant in right eyes was shorter than that of superonasal visual field quadrant in left eyes,and the amplitude of superonasal visual field quadrant in right eyes was longer than that of superotemporal visual field quadrant in left eyes(P<0.05). The P1 latency and amplitude among four visual field quadrants of each eye had significant difference(P<0.05). The P1 latency between the superonasal visual field quadrant and inferotemporal visual field quadrant or between the superonasal visual field quadrant and inferonasal quadrant visual field had significant differences in right or left eyes(P<0.05). Conclusion: The mfVEP of normal subjects exists retinal symmetry.展开更多
Purpose: To investigate the variation of visual function in different eccentricities of the visual field in isometropic amblyopes.Method: The stimulus matrix containing 61 hexagons was generated on a monitor. The diam...Purpose: To investigate the variation of visual function in different eccentricities of the visual field in isometropic amblyopes.Method: The stimulus matrix containing 61 hexagons was generated on a monitor. The diameter of the entire stimulating field was approximately 13.6 deg of arc; the frame rate of the monitor was 67 Hz. Every hexagon of the display contained a number of black and white small hexagonal patches which reversed during stimulation. These hexagons were simultaneously but independently modulated in time by the controlling computer program. The flashed elements were selected differently on each frame according to a computer-generated binary pseudo-random time series (m-sequence); the response contributions from each of the individual stimulus elements could be extracted from the cross corre-ation function. Subjects were asked to maintain fixation at the center of the stimulus pattern while each of the hexagons of the display reversed. The VERB system extracted the local responses by展开更多
Background:To compare objective electrophysiological contrast sensitivity function(CSF)in patients implanted with either multifocal intraocular lenses(MIOLs)or monofocal intraocular lenses(IOLs)by pattern reversal vis...Background:To compare objective electrophysiological contrast sensitivity function(CSF)in patients implanted with either multifocal intraocular lenses(MIOLs)or monofocal intraocular lenses(IOLs)by pattern reversal visual evoked potentials(prVEP)measurements.Methods:Fourty-five cataract patients were randomly allocated to receive bilaterally:apodized diffractive-refractive Alcon Acrysof MIOL(A),full diffractive AMO Tecnis MIOL(B)or monofocal Alcon Acrysof IOL(C).Primary outcomes:1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies.Secondary outcomes:psychophysical CSF measured with VCTS-6500,photopic uncorrected distance(UDVA),and mesopic and photopic uncorrected near and intermediate visual acuities(UNVA and UIVA respectively).Results:Electrophysiological CSF curve had an inverted U-shaped morphology in all groups,with a biphasic pattern in Group B.Group A showed a lower CSF than group B at 4 and 8 cpd,and a lower value than group C at 8 cpd.Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B.Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups.Mesopic UNVA and UIVA were better in group B.Conclusions:Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs.This may be related to the visual acuity under certain conditions or to IOL characteristics.This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.展开更多
文摘Purpose:.To analyze the retinal symmetry of multifocal visual evoked potential (mfVEP) in both eyes of normal subjects. Methods: The monocular mfVEP in both eyes of 36 normal subjects (72 eyes) were tested with VERIS Science 4.0. The stimulus was the pattern reversal dart array consisted of 60 sectors each including 16 black-white reverse patterns. The visual stimulation was controlled by a binary pseudo-random m-sequence and subtended 25 degrees of retinal region. Results: The mfVEP patterns between left and right eyes of each subject were similar, and P1 latency and amplitude in correspondent visual field quadrants between left and right eyes had no significant difference(P>0.05). The latency of superotemporal visual field quadrant in right eyes was shorter than that of superonasal visual field quadrant in left eyes,and the amplitude of superonasal visual field quadrant in right eyes was longer than that of superotemporal visual field quadrant in left eyes(P<0.05). The P1 latency and amplitude among four visual field quadrants of each eye had significant difference(P<0.05). The P1 latency between the superonasal visual field quadrant and inferotemporal visual field quadrant or between the superonasal visual field quadrant and inferonasal quadrant visual field had significant differences in right or left eyes(P<0.05). Conclusion: The mfVEP of normal subjects exists retinal symmetry.
文摘Purpose: To investigate the variation of visual function in different eccentricities of the visual field in isometropic amblyopes.Method: The stimulus matrix containing 61 hexagons was generated on a monitor. The diameter of the entire stimulating field was approximately 13.6 deg of arc; the frame rate of the monitor was 67 Hz. Every hexagon of the display contained a number of black and white small hexagonal patches which reversed during stimulation. These hexagons were simultaneously but independently modulated in time by the controlling computer program. The flashed elements were selected differently on each frame according to a computer-generated binary pseudo-random time series (m-sequence); the response contributions from each of the individual stimulus elements could be extracted from the cross corre-ation function. Subjects were asked to maintain fixation at the center of the stimulus pattern while each of the hexagons of the display reversed. The VERB system extracted the local responses by
文摘Background:To compare objective electrophysiological contrast sensitivity function(CSF)in patients implanted with either multifocal intraocular lenses(MIOLs)or monofocal intraocular lenses(IOLs)by pattern reversal visual evoked potentials(prVEP)measurements.Methods:Fourty-five cataract patients were randomly allocated to receive bilaterally:apodized diffractive-refractive Alcon Acrysof MIOL(A),full diffractive AMO Tecnis MIOL(B)or monofocal Alcon Acrysof IOL(C).Primary outcomes:1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies.Secondary outcomes:psychophysical CSF measured with VCTS-6500,photopic uncorrected distance(UDVA),and mesopic and photopic uncorrected near and intermediate visual acuities(UNVA and UIVA respectively).Results:Electrophysiological CSF curve had an inverted U-shaped morphology in all groups,with a biphasic pattern in Group B.Group A showed a lower CSF than group B at 4 and 8 cpd,and a lower value than group C at 8 cpd.Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B.Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups.Mesopic UNVA and UIVA were better in group B.Conclusions:Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs.This may be related to the visual acuity under certain conditions or to IOL characteristics.This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.
