Comparison of Diabetes Retinopathy Among Type 2 Diabetic Patients Treated With Different Regimens

Inclusion Criteria: 1. aged 30-65; 2. diagnosed to be type 2 diabetes in accordance with the WHO diagnostic criteria in 1999 . 3. diabetes duration for 5 years or less; 4. the glycosylated hemoglobin (HbA1c) is higher than or equal to7.0% ; 5. body mass index (BMI) 20-35 kg/m2; 6. fluorescein fundus angiography (FFA) showed no diabetic retinopathy; 7. women of childbearing-age have birth control plan for 5 years plan; Exclusion Criteria: 1. pregnant or lactating women; 2. diabetes autoantibodies (GAD) antibodies positive; 3. occurred state of diabetic ketoacidosis, diabetes, high permeability, diabetes lactic acidosis within a half years ; 4. aspartate aminotransferase (AST), alanine aminotransferase (ALT) 2.5 times higher than normal ceiling, and/or serum creatinine (Cr) or 133 umol/l (1.5 mg/dl); 5. hemoglobin disease history which can affect determination of HbA1c; 6. have received a coronary angioplasty, coronary artery stent implantation, coronary artery bypass surgery, there was myocardial infarction, unstable angina, and clinical significance of abnormal ecg, cerebrovascular accident, or transient ischemic attack. 7. psychiatric patients; 8. any eye eyesight \< 0.1 patients (WHO blind eye disease: keratitis, need serious cataract surgery, glaucoma, uveitis, high myopia shaft \> 26.5 mm, history of ocular trauma;Other ophthalmology medical history: the central vein occlusion, branch vein occlusion, wet sex senile macular degeneration, etc.; 9. in eye surgery history, history of cataract surgery, and three months; Other serious diseases, the researchers think that don't fit into the patients