TNF-α levels increase after elevating IOP and result in a delayed loss of RGCs. A, Real-time PCR analysis of TNF-α mRNA in the retina at the indicated time points. Results represent fold-increase relative to normal controls. ***p < 0.001 compared with normal control (n = 6 per each time point). B, ELISA for TNF-α protein in the retina. **p < 0.01, ***p < 0.001 compared with normal controls. C, DiI-labeled RGCs in flat-mounted retinas with or without TNF-α injections at 2 or 8 weeks. Scale bar, 50 μm. D, Quantitation of RGC survival at 2 or 8 weeks after intravitreal injection of TNF-α. ***p < 0.001 compared with controls injected with PBS at 8 weeks (n = 8 per time point).