The effects of forward light scattering on the multifocal electroretinogram

Purpose. To study the effects of forward light scattering on the multifocal electroretinogram (mfERG). Methods. Thirty young normal subjects were recruited for this study. The mfERG was measured under five conditions. (1) no light scattering (stimulus contrast 93%), (2) mild light scattering (stimulus contrast 80%), (3) moderate light scattering (stimulus contrast 50%), (4) no light scattering (stimulus contrast 80%), and (5) no light scattering (stimulus contrast 50%). Results. The amplitudes of N1 and P1 from the central retina did not change significantly, but the amplitudes of N1 and P1 in the mid peripheral retina increased with the increase of forward light scattering. By comparing conditions 1, 4 and 5, it was shown that the amplitudes of N1 and P1 decreased at all eccentricities when stimulus contrast reduced from 93% to 50%. Conclusions. This study suggests that the topography and waveform of the mfERG could be affected by forward light scattering.