Normal pattern electroretinograms in amblyopia

Checkerboard reversal stimuli were used to evoke transient pattern electroretinograms (P-ERGs) from the eyes of 14 patients with amblyopia and 14 normal subjects. In the control group, and in normal eyes of patients, pattern electroretinograms were obtained with monocular central fixation. Amblyopic eyes were examined by monocular and binocular fixation, and the fixation point was shifted horizontally and/or vertically until the P-ERG reached its maximal amplitude. After adjusting visual fixation, there were no significant differences in amplitude between the normal and the amblyopic eyes. In addition, the differences between both eyes were compared with the right-left eye variability of the 14 normal subjects. In the amblyopic eyes, no P-ERG abnormality was observed. These results do not support previous reports of reduced P-ERG amplitudes and are in agreement with recent findings obtained under steady-state conditions.