The randomized clinical trial aims to compare the therapeutic effects between panretinal photocoagulation(PRP) and PRP combined with intravitreal conbercept (IVC) injection in severe nPDR with/without diabetic macular edema patients.

This was a prospective, randomized, two-armed study to assess the efficacy and safety of intravitreal conbercept injection plus PRP versus PRP in the treatment of nPDR patients with/without diabetic macular edema for a period of 1 year. This was an investigator-initiated study performed by department of ophthalmology, Ruijin hospital affiliated with Shanghai Jiaotong University School of Medicine.

Inclusion Criteria:

Type II diabetic patients, 18 years and older, were included if the participants had:

1. severe non-PDR in either eyes with/without diabetic macular edema;
2. ETDRS letters-measured best-corrected visual acuity (BCVA) ranging from 20/40 to 20/320 Snellen equivalent;
3. no previous treatment (of any type) in either eye.

Exclusion Criteria:

1. history of prior laser treatment or vitrectomy in the study eye;
2. history of thromboembolic event - including myocardial infarction or cerebral vascular accident;
3. major surgery within the prior 6 months or planned within the next 28 days;
4. history of glaucoma or ocular hypertension;
5. loss of vision as a result of other causes;
6. history of systemic corticosteroid therapy within the last 3 months;
7. severe systemic disease other than diabetes mellitus;
8. known coagulation abnormalities or current use of anticoagulative medication other than aspirin
9. any condition that could affect followup or documentation (including preretinal or vitreous hemorrhage).