METHODS: Sixty patients with type 2 diabetes mellitus with mild or moderate NPDR were treated in our department of endocrinology. They were randomly divided into two groups. Patients in the experimental group used metformin, insulin combined with liraglutide to regulate blood glucose, while the control group used metformin, insulin for hypoglycemia. Comparing the two groups of patients before and after the treatment, including HbA1c and pattern visual evoked potential(P-VEP)P100 amplitude and P100 latency, full field electroretinogram(F-ERG)oscillatory potentials(Ops)total amplitude, and light and dark adaptation 3.0 the amplitude of the a-, b-wave varies.

RESULTS: After 6mo treatment, the total amplitude of Ops in the experimental and control groups increased compared with that before treatment. The difference was statistically significant(all P<0.01). And the total amplitude of Ops in the experimental group was higher than that of the control group, the difference was statistically significant(P=0.049). Meanwhile the b-wave amplitudes of the light and dark adaptation 3.0 in the experimental group were higher than those in the control group(P=0.001, P=0.014); however, there was no statistical significance in a-wave amplitude between the light and dark adaptation 3.0 in both groups after treatment(P=0.505, 0.441, 0.193, respectively). the b-wave amplitudes of the experimental group with dark and light adaptation 3.0 increased compared with that before treatment, and the difference was statistically significant(P<0.01, P=0.019). The a-wave amplitude of light and dark adaptation in the experimental group increased compared with that before treatment, but the difference was not statistically significant(P=0.130, 0.147).

CONCLUSION: GLP-1 analogues can improve the function of retinal neurons in patients with mild to moderate NPDR to a certain extent, and have a positive effect on the prognosis of DR.