Pre-vitrectomy Intravitreal Ranibizumab for Patients With Proliferative Diabetic Retinopathy Combined With Diabetic Macular Edema

Patients will receive single intravitreal injection of Ranibizumab 0.5 mg 3\~7 days before vitrectomy.

Patients will receive single sham injection 3\~7 days before vitrectomy.

Surgical procedure to remove the intravitreal hemorrhage and fibrosis membrane, and re-attach the retina, and perform endo laser photocoagulation on retina