Pre-treatment with TNFα improves retinal ganglion cell survival after crush. Mice were treated with an intraocular injection of TNFα either (A) 5 days prior to optic nerve injury (pre-treatment) for neuronal cell counts 7 and 14 days after crush, or (B) 7 days after crush (post-treatment) and analyzed for cell counts 7 days later (14 days after crush injury). Pre-treatment with TNFα (A) reduced the amount of crush-induced cell loss by 50% 7 days after crush (P <0.001). Although cell loss continued to decline in both cohorts between 7 and 14 days after crush, the protection afforded by pre-treating with TNFα continued to be significant (P <0.001). Post-treatment (B) with TNFα did not affect RGC survival after crush (P >0.05). A single injection of TNFα alone yielded no significant cell loss after (A) 12 days, or (B) 7 days (P >0.05, injected eye relative to contralateral eye). Data are presented as mean ± SE; n ≥3. GCL, ganglion cell layer.