Methods of recording local ERG

: Two methods for recording the retinal local biopotential with the gaze fixation control and without this control are described, to be used for the assessment of the status of any retinal or macular site, among other things. A ring-shaped sucker electrode is employed in both methods; this electrode is supplied with a transparent anterior window and infrared-illuminated mirror in one method and in the other the electrode incorporates a light-emitting diode and an optic system that helps create a 6-20 degrees stimulus. Theoretical analysis and experimental findings evidence that the minimal area on the retina from which a local response may be obtained, fit for clinical purposes, conforms to 10-15 degrees with a stimulus 5 times brighter than semisaturating brightness. The local response share in this case is 70% and the number of possible blendings 50. The results explaining the choice of the conditions for the retinal local biopotential recording are presented. The suggested methods help assess the function of the macular area, distinguish between the functions of the cone and rod systems, record the total and Hanz-Feld electroretinograms without electrode substitution, record the macular biopotential in babies and in patients with nystagmus or with cataracts of various origins.