Objective To observe the opticin expression in the eyes of nonobese diabetes (NOD) mice and nondiabetic NOD mice.Methods Twenty NOD mice were divided into diabetic group (experimental group) and nondiabetic group (control group). All the mice were killed by cervical dislocation method.The eyes were harvested, and the vitreous, retina and sclera were separately collected. Western blot and realtime reverse transcriptionpolymerase chain reaction(RT-PCR)were respectively used to determine opticin protein and OPTC mRNA levels.Results The opticin protein level in the vitreous and retina was lower in the experimental group(t=4.42,4.58;P=0.002,0.002),but is same in thesclera between the 2 groups(t=0.27,P=0.794).OPTCmRNA level was vitreousgt;retinagt;sclera. OPTCmRNA levels of vitreous and retina in diabetic group were significantly lower(t=3.30,2.48;P=0.01,0.04); there was no statistical significant on OPTC mRNA of sclera between two groups(t=0.27,P=0.80).Conclusion Expression of opticin was suppressed in retina and vitreous of diabetic mice.