<unk>  <unk>  is the in-growth of new blood vessels from the pericorneal plexus into avascular corneal tissue as a result of oxygen deprivation. Maintaining avascularity of the corneal stroma is an important aspect of corneal pathophysiology as it is required for corneal transparency and optimal vision. A decrease in corneal transparency causes visual acuity deterioration. Corneal tissue is avascular in nature and the presence of vascularization, which can be deep or superficial, is always pathologically related.<unk>  is a sight-threatening condition that can be caused by inflammation related to infection, chemical injury, autoimmune conditions, immune hypersensitivity, post-corneal transplantation, and traumatic conditions among other ocular pathologies. Common causes of<unk>  within the cornea include trachoma, corneal ulcers, phylctenular keratoconjunctivitis, rosacea keratitis, interstitial keratitis, sclerosing keratitis, chemical burns, and wearing contact lenses for over-extended periods of time. Superficial presentations of<unk>  are usually associated with contact lens wear, while deep presentations may be caused by chronic inflammatory and anterior segment ocular diseases.<unk>  is becoming increasingly common worldwide with an estimated incidence rate of 1.4 million cases per year, according to a 1998 study by the Massachusetts Eye and Ear Infirmary. The same study found that the tissue from twenty percent of corneas examined during corneal transplantations had some degree of<unk> , negatively impacting the prognosis for individuals undergoing keratoplasty procedures.
Corneal neovascularization
Macular corneal dystrophy
Granular corneal dystrophy
Corneal hydrops
Macular edema
Macular scarring
Lattice corneal dystrophy
Interstitial keratitis