The influence of luminance on the multifocal ERG.
OBJECTIVE
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/m(2). 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.


RESULTS
Across all hexagons and subjects, the response density (approximately 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.


CONCLUSIONS
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/m(2). The stimulus luminance range suggested in the mfERG guidelines seems well chosen.
Schimitzek
Thilo
T
Eye Department, Arrowe Park Hospital, Arrowe Park Road, Upton, Wirral, Merseyside, CH49 5PE, UK.
Bach
Michael
M
D000328:Adult; D000704:Analysis of Variance; D004596:Electroretinography / Q000379:methods*; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D013997:Time Factors; D055815:Young Adult