Objective To observe the expression of triggering receptor expressed on myeloid cells (TREM), Caspase-3 and interleukin (IL)-6 in optic nerve tissue of ischemic optic neuropathy (ION). Methods Twenty Sprague-Dawley rats were randomly divided into control group and model group, 10 rats in each group. The permanent ligation of bilateral internal carotid arteries (BICA) was performed for 14 days to establish sub-acute ION model as model group. The control group were separated BICA without ligation. The expressions of TREM-1, TREM-2, Caspase-3 and IL-6 in rat retina were detected by reverse transcription PCR and Western blot, respectively. ResultsCompared with the control group, the expressions of TREM-1, Caspase-3, IL-6 mRNA (t=6.058, 7.86, 6.055) and protein (t=9.671, 9.524, 14.501) in the optic nerve tissue of the model group were increased, while the expression of TREM-2 mRNA and protein (t=9.283) was decreased, and the difference was statistically significant (P＜0.05). Conclusion In ischemic optic nerve tissue, TREM-1 mRNA and protein were significantly expressed, the expressions of TREM-2 mRNA and protein decreased significantly.