The influence of luminance on the multifocal ERG
To assess the efficacy of high luminance in increasing the amplitude of the multifocal electroretinogram (mfERG). We examined 5 male and 5 female volunteers in the age of 22–52 years (median 28 years). Three different stimulus luminance levels were applied: the bright areas of the stimulus pattern were set to 150, 300 and 500 cd/m2. We recorded the potentials via DTL electrodes using the VERIS Science 4.4 system with 61 hexagons, pupils were dilated. Analysis was based on the 5 ring averages.
Across all hexagons and subjects, the response density (∼amplitude) rose by 20% when increasing the luminance by a factor of 3.3. The peak times decreased slightly with higher luminance, by less then 1.5 ms.
Combining the present results with those from two previous studies, the gain (= relative amplitude increase for relative luminance increase) is close to 0.4 over a range of 56–700 cd/m2. The stimulus luminance range suggested in the mfERG guidelines seems well chosen.
KeywordsAmplitude Luminance mfERG Multifocal ERG Peak time
Cathode ray tube
We thank our subjects for their ready cooperation and two anonymous reviewers for thorough critique and valuable suggestions.
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