Figure 9. Evolution of electroretinographic wave amplitudes over a 12-week time period. Average data (mean±SEM) of the reduction in the ERG wave amplitudes is represented as the percentage between operated and unoperated eyes for 1, 2, 4, and 12 weeks after ONT, both from albino (A, C) and pigmented rats (B, D). A, B: Close triangles show averaged amplitudes for the positive scotopic threshold response (pSTR) and open triangles show averaged amplitudes for the negative scotopic threshold responses (nSTR). C, D: Open circles show averaged data for the a-wave amplitudes and closed circles show averaged data for the b-wave amplitude. A permanent reduction in the pSTR and nSTR was observed for the 12-week time period both for pigmented and albino rats. The reduction in the a-wave and b-wave amplitudes recovered earlier in albino rats than in pigmented rats.