Variable array patterns for multifocal electroretinography

The multifocal electroretinography (mfERG) response is associated with using a structured stimulus, usually by an array of hexagonal elements projected in the central 40°-60° degrees of the retina. A series of waves are obtained by mfERG usually with 61,103 and till 241 elements of the stimulus pattern. However, higher resolution of the mfERG system is still an open problem, which improvement requires a higher number of elements in the pattern in order to stimulate the smallest possible retina area. This approach has to overcome many problems related mainly with the low voltage amplitude and response to stray light with amplifier technology. We present in this paper results from a significant reduction in the area of each hexagonal area of stimulus pattern using technology at hand through Itan Technologies RHA2216biosignal amplifier. The paper discusses too a new strategy for the stimuli considering a variety of resolutions, long variable sequences, frame rates and colours. This paper shows the results of stimulation tests performed on healthy human subjects who were stimulated with standard 61 to 153 patterns, which results are compared with our improved proposal from 519 to 1997 hexagonal patterns that improving low voltage cone response and stray light problems.