[4] Corneal neovascularization has become more 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 neovascularization, negatively impacting the prognosis for individuals undergoing keratoplasty procedures.

[1] In advanced stages, corneal neovascularization can threaten eyesight, which is why routine (annual) eye exams are recommended for contact lens patients.

Older estimates cite 128,000 to 470,000 cases of lens-induced CNV each year, but this may be decreasing due to the increasing popularity of daily disposable lenses.

VEGF paves the way for new blood vessel formation by upregulating matrix metalloproteinases production by endothelial cells in the limbal vascular plexus.

The desired results from medical therapy may not always occur, ergo an invasive procedure may be needed to prevent further decrease in corneal avascularity.

Modern rigid gas permeable and silicon hydrogel contact lenses have a much higher level of oxygen transmissibility, making them effective alternatives to help prevent corneal neovascularization.

[6] Using anti-VEGF antibodies to treat CNV has some limitations such as it is not a cure and may require repeated treatments to maintain positive effects over time.

Topical and/or subconjunctival administration of bevacizumab or ranibizumab have demonstrated short-term safety and efficacy,[4] however long term effects have not been documented.

Complications can include irradiation from previously injected photosensitive dye inducing apoptosis and necrosis of the endothelium and basement membrane.

[8] Some evidence exists to suggest that the Angiotensin II receptor blocker drug telmisartan will prevent corneal neovascularization.