Figure 4

Multifocal electroretinography (mfERG) of the two patients. A: the right eye of case 1. B: the left eye of case 1. C: the right eye of case 2. D: the left eye of case 2. The images indicated reduced focal responses with a decrease in amplitude and prolonged peak latency of N1 and P1 responses in both eyes. In case 1, the amplitude of N1 and P1 of ring 1,2,3,4,5 remarkably diminished, and the peak latency of N1 and P1 responses were both delayed. In case 2, there were a decrease in amplitude and prolonged peak latency of N1 and P1 responses in both eyes, especially in the ring 1 and 2.