Treatments for Corneal Neovascularization: A Review

Abstract

Corneal neovascularization (CNV) may be a physiological response to various stimuli, but a chronic and persistent upregulation of neoangiogenesis can result in pathological CNV. Pathological blood vessels are immature and lack structural integrity, predisposing the cornea to lipid exudation, inflammation, and scarring. CNV can therefore become a potentially blinding condition. In this review, we frame CNV in an epidemiological perspective, consider risk factors for CNV, provide an overview of CNV pathogenesis, and consider the impact of CNV on corneal transplantation. We consider treatments that are of largely historical interest, before reviewing contemporary medical and surgical treatments. Within medical treatments, we report on steroids, nonsteroidal anti-inflammatory agents, antivascular endothelial growth factor agents, and cyclosporine. Within surgical treatments, we report on the use of lasers, photodynamic therapy, superficial keratectomy, and diathermy/cautery-based treatments.

Fine Needle Diathermy and Intraestromal Bevacizumab: A Combined Treatment for Corneal Neovascularization

“…It might not be effective in patients where angiogenesis also depends on different citokines not blocked by Bevacizumab. 1 Previous studies have shown the efficacy of topical and sub-conjunctival bevacizumab for corneal neovascularization. The disadvantages of these ways of administration are the diminished penetration and absorption of the drug through the intact corneal epithelium due to its high molecular weight (149 kDa) and the lacrimal clearance, the potential effects of sub-conjuntival administration such as thinning and erosion of the corneal epithelium, conjunctiva and sclera and the high costs of topical preparations.…”

“…Compared to topical corticosteroids, studies do not report important side effects, otherwise bebacizumab tends to be used as adjuvant to corticosteroids rather than to replace them. 1 Intrastromal bevacizumab for corneal neovascularization studies have shown hopeful results 5,7-9 due to its optimal intracorneal therapeutic levels and it also guarantees a better compliance compared to other ways of administration. 4 Nontheless should the security of intraestromal injection be studied.…”

“…Subsequently, corneal neovascularization may lead to reduced visual acuity and worsening of penetrating queratoplasty prognosis after the alteration of the well-known immune privilege of the cornea. [1][2][3][4] Prevalence of corneal neovascularization in the United States is known to be 4.14%, presenting 12% of the cases in association with visual loss. 1,2 The leading causes of corneal neovascularization are known to be infections, contact lens misuse and the vascular response associated to corneal transplantation.…”

“…[1][2][3][4] Prevalence of corneal neovascularization in the United States is known to be 4.14%, presenting 12% of the cases in association with visual loss. 1,2 The leading causes of corneal neovascularization are known to be infections, contact lens misuse and the vascular response associated to corneal transplantation. Now-a-days there is a variety of treatments for corneal neovascularization such as topical corticoesteroids and non-steroidal anti-inflammatories, anti-angiogenic therapies such as bevacizumab, ciclosporine A, diathermy direct occlusion of vessels, topical ascorbic acid, criotherapy, photodynamic theraphy, laser photocoagulation and superficial queratectomy.…”

Comparison of the effects of subconjunctival and topical anti-VEGF therapy (bevacizumab) on experimental corneal neovascularization

“…Medical treatments may also include non-steroidal anti-inflammatory agents such as rapamycin, cyclosporine A, gene therapy approaches, methotrexate, and anti-VEGF agents. Laser and surgical treatments include the use of argon lasers, yellow lasers, Nd:YAG lasers, superficial keratecto my, diathermy, cauterization, and photodynamic therapy (16) . VEGF is a family of proteins comprising VEGF-A, -B, -C, and -D, the viral VEGF homologue VEGF-E, and placental growth factor (10) .…”