Evaluation of the evolution of patients with vitreous hemorrhage caused by proliferative diabetic retinopathy subjected to intravitreal injection of antivascular endothelial growth factor (bevacizumab)

The microvascular complications of diabetes mellitus in the retina, defined as diabetic retinopathy (RD), constitute one of the main causes of blindness of the economically active population in Brazil and the world. Macular edema is the main cause of low visual acuity, however the proliferative form of RD is that it relates more frequently to severe visual loss. The presence of vitreous hemorrhage in patients with proliferative diabetic retinopathy is one of the main causes of severe visual acuity low in these patients. Vitreous hemorrhage that evolves without spontaneous absorption can significantly affect visual rehabilitation and require additional surgical procedures for improvement of the vision. The growth factor endothelial (VEGF) is expressed in high levels in the retina of diabetic retinopathy patients and are directly related to the formation of new vessels. By promoting a leukocyte migration and adhesion on the wall of vascular endothelial cells, increases vascular permeability and angiogenesis, with consequent progression of diabetic retinopathy. Inhibition of vascular growth factor may induce proliferative diabetic retinopathy regression and combat the exuding phenomenon. Bevacizumab (Avastin; Genentech, INC, South San Francisco, CA) is a monoclonal recombinant antibody against VEGF. Intravitreal injections of bevacizumab has been widely used in the treatment of different manifestations of proliferative diabetic retinopathy, such as progressive retinopathy active, before or combined with vitrectomy via pars plana (VVPP), severe retinal neovascularization or as a preoperative adjuvant to facilitate the surgery of VVPP. The vitreous hemorrhage presents itself as an evolution of this rigged angiogenesis process. The VVPP is the gold standard treatment for vitreous hemorrhage with or without tractional retinal detachment secondary proliferative diabetic retinopathy. Despite the VVPP having a high anatomical success rate, this procedure may be associated with surgery induced complications such as recurring vitreous hemorrhage, neovascular glaucoma, tractional retinal detachment and cataract. Such complications can compromise visual results. Moreover, a significant increase in the monetary cost of treatment. Until the present moment, there are few works that aims to evaluate whether patients presenting vitreous hemorrhage without retinal detachment, when subjected to VEGF intravitreal injections, has higher rates of spontaneous reabsorption of hemorrhage with consequent reduction in the need for surgery indication.