Related Experiment Video
Updated: May 14, 2026
Multifocal Electroretinograms
Published on: December 4, 2011
Differential effects of optic media opacities on mfERGs and mfVEPs
Objective:
To assess different effects of image degradation that could result from optic media opacities on multifocal retinal (mfERG) and cortical responses (mfVEP).
Methods:
Monocular flash-mfERGs and pattern-reversal mfVEPs were recorded. MfERG-P1 amplitudes and implicit times and mfVEP root-mean-square values (RMS) and delays were compared for different filter conditions (none, 8% luminance, 50% luminance, 50% luminance plus blur) in a total of ten participants with normal vision.
Results:
Reducing stimulus luminance down to 50% and 8% reduced mfERG amplitudes to 86% and 42%, respectively, with no significant effect on mfVEP amplitude. Implicit times were increased for mfERGs by 0.9 ms and 6.0 ms, respectively, and for mfVEPs by 1.0 ms and 6.3 ms, respectively. For '50% luminance plus blur' mfERG amplitudes were significantly reduced centrally and enhanced peripherally and delayed by 1.3 ms. MfVEPs were reduced close to noise level independent of eccentricity.
Conclusions:
Degradation of the retinal image is a potential source of discrepancies between mfERGs and mfVEPs. Image blur suppresses the mfVEP at all locations and changes mfERG topography, resulting in a selective loss of central responses.
Significance:
Considering optic media opacities is of importance for the correct interpretation of mfERG and mfVEP recordings, particularly in elderly patients.
Insights
Image degradation from optic media opacities significantly impacts multifocal electroretinography (mfERG) and multifocal visual evoked potentials (mfVEP) differently. Blur specifically suppresses mfVEP and alters mfERG topography, affecting central responses.
Area of Science:
- Ophthalmology
- Neuroscience
- Visual Electrophysiology
Background:
- Optic media opacities can degrade retinal image quality.
- Understanding their impact on visual electrophysiological tests is crucial for accurate interpretation.
Purpose of the Study:
- To evaluate how image degradation affects multifocal electroretinography (mfERG) and multifocal visual evoked potentials (mfVEP).
- To compare the differential effects of luminance reduction and blur on mfERG and mfVEP.
Main Methods:
- Monocular flash-mfERGs and pattern-reversal mfVEPs were recorded in ten healthy participants.
- Responses were analyzed under various filter conditions: no filter, 8% luminance, 50% luminance, and 50% luminance with blur.
Main Results:
- Reduced luminance significantly decreased mfERG amplitudes but had minimal effect on mfVEP amplitudes.
- Both mfERG and mfVEP showed increased implicit times/delays with luminance reduction.
- Blurring with 50% luminance suppressed mfVEPs across all eccentricities and altered mfERG amplitudes (central reduction, peripheral enhancement) and delays.
Conclusions:
- Image degradation, particularly blur, causes discrepancies between mfERG and mfVEP.
- Blurring selectively suppresses mfVEP and alters mfERG topography, impacting central visual function.
- Accurate interpretation of mfERG and mfVEP requires consideration of optic media opacities, especially in older adults.
