Figure 5. Illustration showing the average number of cells/mm² for all four types of epiretinal membranes. The brackets at the left of Table 1 show which membranes were used to generate this figure. For each membrane type (i.e., disease condition) the average number of cells/mm² equals the total number of nuclei/mm (gray bars) divided by the number of epiretinal membranes (ERMs) in the group. The average number of glial cells (green bars) equals the number of glial fibrillary acidic protein (GFAP) positive cells that were also labeled with K_i-67/mm² in each ERM divided by the number of ERMs in the group. The value for immune cells (ricin labeled cells, blue bars) was calculated the same way while “unidentified” equals the value for cells that were K_i-67 positive but not labeled with any other markers (black bars). Proliferative vitreoretinopathy (PVR) membranes had the highest number of dividing cells. Abbreviations: proliferative diabetic retinopathy (PDR); proliferative vitreoretinopathy (PVR); post–retinal detachment (ERMpRD); idiopathic ERM (iERM).