Inclusion Criteria:

• Significant unilateral or bilateral corneal neovascularization that extending over the limbus at least 2mm.
• The underlying etiologies that caused corneal neovascularization included post penetrating keratoplasty (PKP), ocular surface reconstruction , trauma, infectious or non-infectious corneal ulcer.
• Corneal neovascularization induced lipid keratopathy, corneal edema, or irregular corneal surface. The best-corrected visual acuity was less than 20/25.
• Post-PSP or ocular surface reconstruction corneal neovascularization that had no associated lipid keratopathy, no corneal edema, or corneal irregularity. But the neovascularization was highly possible to cause graft rejection.
• The corneal neovascularization was refractory to other medical treatment.
• The patient had received PKP or other corneal surgeries mort than half a year ago and was not in the acute post-operation phase.
• The patient had no active endophthalmitis, glaucoma with uncontrolled intraocular pressure, or vitreoretinal diseases.
• The patient signed inform consent to have regular follow up and treatment.

Exclusion Criteria:

• The neovascularization had clinical improvement three months before the first injection.
• The lipid keratopathy had clinical improvement three months before the first injection.
• The patient that suspected to have poor visual outcome or had already been light sense negative Glaucoma patient that had uncontrolled intraocular pressure.
• Poor corneal epithelialization.
• Patient that had systemic disease which was not suitable for bevacizumab use.
• Pregnant patient.