Denden A
Klin Monbl Augenheilkd. 1977 Jun;170(6):925-33.
A single-flash ERG and an EOG were performed in four cases of fundus heterotopicus. While the EOG responses showed a normal light and dark adaptation, the ERG registered a subnormal a- and b-wave, corresponding to the extent of the medial ectasia. Where hemeralopia was present, the ERG showed a monophasic a-wave and a markedly reduced b-wave. That means that in addition to the simple fundus heterotopicus, there is also a form with several clinical characteristics in which a hemeralopia is adaptometrically and electroretinographically demonstrable.