Antiangiogenic therapy for ocular diseases: Current status and challenges

Angiogenesis is the process of new blood vessel growth from pre-existing ones involving vascular endothelial cell activation, proliferation, migration, and tube formation. The vascular endothelial growth factor A (VEGF-A) is known to be a key factor that promotes angiogenesis. Pathological angiogenesis is a key and common feature of numerous ocular neovascular diseases, such as wet age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, retinal vein occlusion, and corneal neovascularization. Although anti-VEGF treatment has been a great success for the treatment of such ocular neovascular diseases, many challenges exist, such as limited efficacy, unresponsiveness in many patients, drug resistance, treatment burden due to repeated intravitreous injection, all of which incent much effort and enthusiasm to find new and better treatment for ocular neovascular diseases. In recent years, new antiangiogenic drug, targets and drug delivery methods have been developed. This perspective discusses the status of currently available therapies, challenges, opportunities, and potential new directions toward better therapies for ocular neovascular diseases.