EPO levels drop rapidly immediately after intraocular injection, the half-life of EPO is 1 hour post-injection. The amount EPO detected reaches previously published neuroprotective levels 5–13hrs post-injection (Grimm et al., 2004; Kilic et al., 2005; Ranchon Cole et al., 2007). A. Whole eye EPO levels at 0, 15, 30, 60, and 180 min post-injection. B. EPO levels 6, 14, 24, 30, and 36 hours post-injection. Error bars represent S.E.M.