VEGFA and retinal vein occlusion: Ranibizumab is a humanised antigen-binding fragment (Fab) that targets all isoforms of vascular endothelial growth factor A (VEGF-A) and is approved by the Food and Drug Administration for the treatment of patients with neovascular age-related macular degeneration (AMD), as well as diabetic macular oedema and macular oedema following retinal vein occlusion.