This study is to investigate the effect of adjunctive intravitreal bevacizumab (IVB) before panretinal photocoagulation (PRP) compared with only PRP on central macular thickness and retinal nerve fiber layer thickness in patients with severe diabetic retinopathy without macular edema.

This prospective randomized study included 30 patients (60 eyes) with severe nonproliferative diabetic retinopathy or non-high-risk proliferative diabetic retinopathy. They had weekly PRP treatments in 3 sessions and they were randomly assigned to IVB group who had adjunctive IVB within 1 week before first PRP and control group who had only PRP. CMT, RNFL, and best-corrected visual acuity (BCVA) were measured

Inclusion Criteria:

• patients with severe NPDR or early PDR without macular edema
• best-corrected visual acuity (BCVA) of 20/25 or better
• patients who were followed up for at least 6 months after the first PRP.

Exclusion Criteria:

• patients with retinal or choroidal diseases except diabetic retinopathy
• contraindications to fluorescein angiography (FA) or bevacizumab
• patients who had previous treatments including anti-angiogenic medications and laser photocoagulation
• patients with previous vitrectomy
• patients with uncontrolled hypertension, a recent myocardial infarction or cerebral vascular accidents.