MERGs from three of the ABCA4
carriers (subject 4, top row; subject 5, second row; and subject 8, third row). The bottom row illustrates a normal mERG
in one of the controls. Subject 4 has reduced mERG amplitudes and delayed ITs, although the fundus photos do not show any
changes. Subject 5 also has reduced mERG amplitudes and delayed ITs. In this subject, the mERG alterations are accompanied
by pigmentary changes in the macula (Figure 1B, C
). Subject 8 with quite widely spread retinal flecks (Figure 1J, K
) demonstrates delayed mERG ITs but normal mERG amplitudes.