IMAGING LOCALIZED RETINAL DYSFUNCTION WITH THE MULTIFOCAL ELECTRORETINOGRAM

Conventional electroretinographic techniques do not permit efficient m apping of retinal responsiveness for the detection of small dysfunctio nal areas. This study explores the application of a new technique that makes such mapping possible. It utilizes a multifocal electroretinogr am technique based on binary m sequences that simultaneously tests a l arge number of small retinal areas by multiplexing their responses ont o a single signal derived from the human cornea. The focal responses a re subsequently extracted for the derivation of high-resolution maps t hat characterize retinal responsiveness. The required recording times are short enough to make such testing feasible in the clinic. In this study we demonstrate the high sensitivity of the technique by mapping a small area that has been partially bleached by a strobe flash in a n ormal retina and by mapping dysfunctional areas in three patients with different, well-documented retinal pathologies. The results suggest t hat the multifocal electroretinogram has the potential to become a val uable clinical tool. (C) 1996 Optical Society of America