Inflammatory corneal neovascularization: etiopathogenesis.

There is a delicate balance between pro-angiogenic stimuli and anti-angiogenic stimuli in the normal cornea. This balance allows the cornea to normally exist in a relatively avascular state, which is needed for optical clarity and vision. However, in the setting of inflammation, this balance may be shifted in favor of neovascularization. This paper reviews the literature on corneal inflammatory neovascularization beginning with the pro-angiogenic factors, such as Vascular Endothelial Growth Factor and Fibroblast Growth Factor, which help to facilitate the development of new corneal vessels. Subsequently the anti-angiogenic factors and their role in preventing neovascularization in the normal cornea are reviewed. Finally, a review of several etiologies of inflammatory neovascularization is presented with attention to the processes that allow the pro-angiogenic stimuli to overwhelm the anti-angiogenic factors.