Figure 8. Quantification of TUNEL-positive cells in the outer nuclear layer of affected dogs. Apoptosis analysis was performed with fluorescent microscopy and a 40× objective. Terminal dUTP nick end labeling (TUNEL) positive cells stained with fluorescein were visualized and counted. TUNEL-positive cells in the outer nuclear layer (ONL) were quantified as the percent of the total number of cells in ONL per field. Data are the mean±standard error of the mean from 10 fields of view. The graph represents the average of 3 independent experiments. Months are abbreviated as m.