AIM: To evaluate the early diagnosis of sub-clinic stage of diabetic retinopathy.

METHODS: This was cross sectional study,multifocal retina electroretinogram(mf-ERG), contrast sensitivity(CS)and central retinal artery color Doppler examination were recorded from 30 cases(30 eyes)matched control subjects, 35 cases(35 eyes)with type 2 diabetes mellitus(DM)without diabetic retinopathy(NDR)and 38 cases(38 eyes)with non-prolifera tive diabetic retinopathy(NPDR). One-way ANOVA and SNK-q test were used for data analysis.

RESULTS: P1 response density of NDR patients were found decrease, N1 implicit time were delayed. Which were related with the degree of retinopathy(P<0.05); CS of NDR patients were found significant in middle and high frequency(P<0.05), NPDR patients were found significant in full frequency(P<0.05); Central retinal artery(CRA)blood flow in the control groups and NDR groups were not found statistically significant(P>0.05), The differences between normal group, NDR group and NPDR group were found statistically significant(P<0.05).

CONCLUSION: mf-ERG and CS are sensitive indexes for early evaluation of visual function in patients with diabetes mellitus, with development of the disease, CRA blood flow also appears to decline.