Experimental protocol and animal groups. ONC was performed followed by the appropriate intravitreal injection. At 1, 2, or 4 weeks post-ONC, rats from each group were euthanized and the tissue was analyzed (A). Both 1 and 2 week time points included the groups: saline, CNTF (0.5 μg), RTG-CNTF (0.5 μg), and SRTG-CNTF (0.5 μg) (n = 3–5). The 2 and 4 week time points also included the group: SRTG-CNTF (2.5 μg) (B).