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Reproducibility of the mfERG between instruments.
Wendy W Harrison1, Marcus A Bearse, Jason S Ng
1University of California Berkeley School of Optometry, 94720-2020, USA. wwh@berkeley.edu
Documenta Ophthalmologica. Advances in Ophthalmology
|March 27, 2009
Summary
Reproducibility of multifocal electroretinogram (mfERG) recordings is high when using Z-scores, even with different amplifiers or instruments. Converting mfERG data to Z-scores allows effective comparison across multicenter and longitudinal studies.
Area of Science:
- Ophthalmology
- Neuroscience
- Medical Instrumentation
Background:
- The multifocal electroretinogram (mfERG) is crucial for assessing retinal function.
- Variability in mfERG recordings across different instruments and amplifiers can hinder multicenter and longitudinal studies.
- Standardizing mfERG data acquisition and analysis is essential for reliable research.
Purpose of the Study:
- To evaluate the reproducibility and repeatability of mfERG recordings using different amplifiers and instrument versions.
- To establish a method for comparing and combining mfERG data from multiple recording instruments.
- To enhance the utility of mfERG in multicenter and longitudinal research.
Main Methods:
- mfERG recordings were made using two software versions (VERIS 4.3 and VERIS Pro 5.2) and three amplifiers.
- 73 subjects with normal vision and 26 with diabetes were tested across different recording setups.
- P1 implicit times and N1-P1 amplitudes were measured, and differences were analyzed as raw scores and Z-scores.
Main Results:
- Different amplifiers produced variations in mfERG implicit times, but amplitudes were comparable.
- mfERG recordings on different days and instruments showed more variability, particularly in amplitudes.
- Z-score conversion improved agreement between instruments, with a 95% confidence interval of approximately +/-1 Z-score for implicit times.
Conclusions:
- mfERG implicit times can differ significantly between amplifiers, even with identical settings.
- mfERG Z-scores demonstrate high reproducibility across different recording instruments.
- Converting mfERG data to Z-scores based on normative data is vital for comparing and combining data in multicenter and longitudinal studies.
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