This is a prospective, randomized and comparative study is to quantify the functional and structural alterations of the macula in patients with proliferative Diabetic Retinopathy submitted to laser photocoagulation and to evaluate the efficacy of intravitreal bevacizumab as a adjuvant therapy in preventing the adverse events of that procedure. The patients with proliferative Diabetic Retinopathy (DR) with indication of binocular laser photocoagulation will be examined by ophthalmologists who will measure the visual acuity and contrast sensitivity, perform slit lamp examination, fundus examination and optic coherence tomography before and after laser photocoagulation. Laser photocoagulation will be performed in both eyes according Early Treatment Diabetic Retinopathy Study that advocate the realization of 3 episodes of laser photocoagulation in 3 weeks. This comparative study analyses the effect of intravitreal bevacizumab one week before laser photocoagulation and one, three and six months after the randomization visit. The fellow eye will be submitted only to laser photocoagulation and will be considered as control. It is estimated a sample of 30 patients. All procedures, purposes and methods will be explained to all patients.