[ERG characteristics of congenital stationary night blindness].

The ERG of 9 cases (18 eyes) of congenital stationary night blindness with normal fundi or myopia were tested. All eyes showed absence of rod ERG and cone ERG with normal a-wave. Scotopic mixed ERG were of the negative type in 7 eyes and the subnormal type in 11 eyes. The b/a ratio was reduced in all eyes. The ERG characteristics are useful for the classification, estimation of the probable location of the lesion, and differential diagnosis of the disease.