Given that photocoagulation, the treatment of choice for diabetic retinopathy, has side effects of affecting the field of view and limiting night vision, the authors of this review16 investigated the efficiency and effectiveness of use of vascular endothelial growth factor (VEGF) as a treatment that might preserve the vision of patients with proliferative diabetic retinopathy. This evidence concerns the gene VEGFA and proliferative diabetic retinopathy.