Role of the Serum Exosomal miRNA in Diabetic Retinopathy (DR)

Patients will be chosen according to the inclusion and exclusion standard and written informed consent will be obtained from all participants.

Exit criteria： During the research, for his / her own consideration or at the request of the investigator the patient may withdraw from the trial at any time. For each subject who withdrew from the trial, the investigator must detail the subject's exit date, the reason, and other information in case report form（CRF）.

Inclusion Criteria:

• Type II diabetics,
• Age > 18 years old,
• Have not accepted anti-VEGF therapy,
• Without turbid ocular media or corestenoma that interfere with ophthalmic fundus examination (patients with PDR are excluded).

Exclusion Criteria:

-Patients with any following eye disease in studied eye:

1. active infections (i.e., blepharitis, keratitis, scleritis, conjunctivitis, etc.),
2. fundus oculi diseases other than DR (i.e., retinal vein occlusion, choroidal neovascularization, retinal detachment, macular hole, vitreous traction in macular region, epiretinal membrane, etc.) ,

3. uncontrollable glaucoma (intraocular pressure is no less than 25mmHg after anti-glaucoma agents) or after filtering surgery for glaucoma;

   -Patients who have accepted any following treatment in studied eyes:

4. intraocular injection of corticosteroids (i.e., Triamcinolone) within 3 months, or peribulbar injection of corticosteroids within 1 months,
5. vitrectomy surgery,
6. anti-VEGF therapy for eyes or other parts of the body (i.e., ranibizumab, bevacizumab, conbercept, aflibercept, pegaptanib sodium, etc),
7. any intraocular surgery within 3 months (i.e., cataract surgery, YAG laser capsulectomy, etc),

8. ocular surgery related with macular region;

   -Patients with any following systemic diseases:

9. failed blood sugar control within 3 months (Changing treatment from oral antidiabetic therapy into insulin treatment, or start using insulin pump, or doubling the number of injections),
10. damaged renal function (Crea is found to be 2 times higher than the upper limit in central laboratory) or abnormal liver function (ALT, AST are found to be 2 times higher than the upper limit in center of the laboratory),
11. failed blood pressure control within 3 months (systolic blood pressure is no less than 140 mmHg or diastolic blood pressure is no less than 90 mmHg after hypotensor treatment),
12. systemic infection that requires oral, intramuscular or intravenous administration,
13. stroke, transient ischemic attack, myocardial infarction or acute congestive heart failure within 6months,
14. coagulation dysfunction (thrombin time ≥ normal upper limit of 3 seconds, activation of partial thromboplastin time ≥ normal upper limit of 10 seconds),
15. using drugs that may be toxic to the lens, retina or optic nerve during this research (i.e., deferoxamine, chloroquine, hydrogenated chloroquine (chloroquinol), tamoxifen, phenothiazine, or ethambutol, etc.),

16. diagnosed systemic immune diseases (i.e., mandatory spondylitis, systemic lupus erythematosus, etc.) or any uncontrollable clinical diseases (such as AIDS, malignancy, active hepatitis, severe mental, neurological, cardiovascular, respiratory and other systems diseases, etc.);

    -Others:

17. pregnant and lactating women,
18. those who participated in any drug clinical trials (not including vitamins and minerals) within 3 months,
19. those researchers believe that need to be excluded.