CASP6 and ischemia: Ligation of the ophthalmic vessels produces a uniform ischemic injury in the inner retina, the location of RGC cell bodies (Figures 1a–k).6 We delivered Z-VEID-FMK (CASP6 inhibitor) or Z-IETD-FMK (CASP8 inhibitor) by intraocular injections at 3 and 10 days after ischemia, and the survival of Fluorogold pre-labeled RGCs was quantified at 14 days post ischemia.