In 2010, the US FDA approved the use of Lucentis intravitreal injections for macular edema; then in 2013, the National Institute for Health and Care Excellence in the UK also approved it to be used for the treatment of macular edema caused by diabetes and/or retinal vein occlusion.
Ranibizumab (trade name Lucentis among others) is a monoclonal antibody fragment (Fab) created from the same parent mouse antibody as bevacizumab. It is an anti-angiogenic that has been approved to treat the "wet" type of age-related macular degeneration (AMD, also ARMD), diabetic retinopathy, and macular edema due to branch retinal vein occlusion or central retinal vein occlusion. The drug is injected intravitreally (into the vitreous humour of the eye) once a month. Intravitreal injection A 2017 systematic review update found that while ranibizumab and bevacizumab provide similar functional outcomes in diabetic macular edema, there is low-certainty evidence suggesting that ranibizumab is more effective in reducing central retinal thickness than bevacizumab. Concerning repeated injections after retinal vein occlusion two different procedures are in use, fixed schedule or pro re nata (PRN = as needed). 
