Components of the human electroretinogram; an analysis in normal eyes and in colour blindness; preliminary report.

Abstract

Summary. 1 On stimulation with strong flicker of equal light and dark intervals and 1 stimulus/sec., it has been found possible in man to obtain an electroretinogram (ERG) with two negative and four positive waves. 2 In normal eyes, adaptation to red light leads to temporary disappearance of the 3rd positive wave, whereas pre-adaptation to green light enhances the 4th positive wave. 3 The third, red-sensitive component was lacking in two pro-tanopes. This component was present in the third protanope, but was not influenced by adaptation to red light. 4 A deuteranope exhibited the ordinary ERG but, whereas adaptation to red light enhanced the third positive component in the usual way, the ERG was uninfluenced by adaptation to green light. One patient with deuteranomalopia had an ERG similar to that of normal eyes. 5 In two totally colour-blind patients, a photopic ERG was entirely lacking. 6 The red-sensitive component is in agreement with experiences of the photopic ERG published earlier. The 4th positive wave is presumably a photopic function, although a specific green-sensitive component cannot be ruled out. Some properties of the two negative waves are briefly discussed.