METHODS: This was a cross-sectional study. Patients with type 2 diabetes who had been treated in ophthalmology department of Shanghai Tongren Hospital were invited to participate in this study during January 2018 to September 2018. To evaluate clinical characteristics, each subject completed diabetes related history questionnaire, laboratory examination(blood glucose, glycosylated hemoglobin, blood lipid), eye examination(vision, intraocular pressure, slit lamp examination, corneal topography, fundus photography, OCT). According to the severity of retinopathy, patients were classified to three groups: group 0: none DR, group 1: mild and moderate NPDR, group 2: severe NPDR and PDR. Chi-square test, t-test and variance analysis were used to analyze the differences between groups, and risk factors of DR were studied through Logistic regression analysis. Then analyzed whether these risk factors would affect the biological structures of the anterior segment, such as refractive index, corneal thickness, corneal curvature and anterior chamber depth.

RESULTS: Totally 219 diabetic patients participated in the survey, and 56 patients(25.6%)were diagnosed with DR. The age of DR patients \〖(66.84±15.13a)(group 1)/(65.45±12.83a)(group 2)\〗 was higher than that of patients without DR(59.59±14.61a)(P<0.05). The course of diabetes in DR patients \〖(13.69±10.22a)(group 1)/(15.23±8.22a)(group 2)\〗 was higher than that in patients without DR(9.21±7.92)a(P<0.05).The proportion of diabetic nephropathy in DR patients \〖(28.0%)(group 1)/(32.3%)(group 2)\〗 was higher than that those without DR(14.1%)(P<0.05).The proportion of DR patients treated with insulin \〖(64.0%)(group 1)/(83.9%)(group 2)\〗 was higher than those without DR(44.2%)(P<0.05). Logistic regression analysis showed that the course of diabetes, diabetic nephropathy and insulin were the risk factors of DR(OR>1, P<0.05). All of the above risk factors will significantly reduce the corrected vision of DR patients.The corneal thickness of patients with DR(550.82±34.73)μm was greater than those without DR(542.37±33.32)μm(P<0.05). The anterior chamber depth of patients with diabetes over 10a(2.49±0.43)mm was less than those with diabetes less than 10y(2.68±0.40)mm(P<0.05).

CONCLUSION: The course of diabetes, diabetic nephropathy and insulin use were the risk factors for DR. Patients with long duration of diabetes had a shallower anterior chamber depth.