Posters

Bevacizumab and corneal pathology

Poster Details

First Author: M.Bilen Babić CROATIA

Co Author(s):    M. Merlak                    

Abstract Details

Purpose:

Review of the current literature on anti-vascular endothelial growth factor (VEGF) bevacizumab therapy for corneal neovascular disorders. Cornea is unique avascular, immunoprivileged connective tissue that acts as transparent mechanical barrier and the anterior eye refractive surface. Corneal neovascularizations (NV) are caused by chronic corneal ischemia with pathological ingrowths of perylimbal blood vessels into the cornea. Abnormal blood vessels cause corneal scarring and compromise visual acuity. Pathological conditions that cause corneal neoangiogenesis are chemical burns, ischemia, infections, degeneration, trauma and immune processes. Corneal neoangiogenesis affects about 1,4 million people a year.

Setting:

Bevacizumab can be used in NV tretment caused by: inflammatory diseases (pemphigoid, rosacea, transplant rejection), infections, pterygium, ocular surface squamous neoplasia, traumatic/iatrogenic causes (chemical injury, contact lens wear NV).Studies have demonstrated partial reduction of neovascularization through topical, subconjunctival and intrastromal bevacizumab application.

Methods:

Topical bevacizumab administration in clinical studies: 1% (10mg/ml) bevacizumab 4 times/day; 0,5% (5 mg/ml) bevacizumab for 0,5-12 months (5 times/day), 1% topical bevacizumab for 2-4 times/day for 3 weeks. Topical 5 mg/ml 4 times daily during 8 weeks can be used as reductive treatment for squamous neoplasia of conjunctiva and cornea. Subconjunctival bevacizumab application: 2,5 mg/0,1 ml; 3 injections of 2,5 mg/0,1 ml bevacizumab. Intrastromal application: 1-2 subconjunctival詻歪쭫ꉦ� injections (1,25 mg/0,05 mL) at 1-month intervals, deep intrastromal (2,5 mg/0,1 mL) bevacizumab after deep anterior keratoplasty; 27-gauge needle 2,5 mg/0,1 ml deep intrastromal paracentral injection.

Results:

Bevacizumab is apparently effective only against proliferating new blood vessels, so it is optimal to use it in early neoangiogenesis. Excluding factors for use are: pregnancy, uncontrolled blood pressure and history of heart attack and cerebrovascular accident. Topical use can lead to corneal epithelial defects and thinning, shorter duration of therapy with lower concentrations (0,5-1,0%), can improve the safety profile of topical bevacizumab.Side effects of subconjunctival and intracorneal use are rare.Subconjunctival bevacizumab is better for focal, deep and peripheral neovascularization, while the diffuse superficial neovascularization with central changes are best treated by topical application.

Conclusions:

Anti-VEGF agents have created enormous hope for the treatment of corneal neovascularization. Treatment of corneal NV with anti-VEGF antibody has limits and depends on the size of the scar, durability and range of neovascularization. Anti-VEGF agents are especially effective when administered early (less then 2 weeks) in neoangiogenesis). Controlled prospective studies are needed to establish long-term safety, efficacy and minimum effective and maximum security concentration of the drug to treat neovasculariosation of anterior eye segment.

Financial Disclosure:

NONE