The investigators aim to demonstrate the efficacy and safety of subconjunctival injection of Avastin as an adjunctive therapy for Ahmed valve glaucoma implant in patients with refractory glaucoma.

Several studies have revealed evidences on the substantial role of Vascular endothelial growth factor-A (VEGF-A) in enhancing neovascularization processes. Some studies have shown the efficacy of intravitreal Avastin in reducing level of VEGF-A to improve NVG. On the other hand, recent pathological studies demonstrated that neutralization of VEGF reduced vascularity and decreased scar formation during wound healing, showing that VEGF strongly influence scar tissue formation. This may reduce the formation of encapsulated cyst after glaucoma surgeries and thus might improve the surgical success rate. The effect of subconjunctival bevacizumab as an adjunctive therapy in filtering glaucoma surgeries has been recently illustrated.

We aim to demonstrate the efficacy and safety of subconjunctival injection of Avastin as an adjunctive therapy for Ahmed valve glaucoma implant in patients with refractory glaucoma.

Inclusion Criteria:

• Clinical diagnosis of refractory glaucoma defined as uncontrolled IOP (> 21 mm Hg) despite maximal antiglaucoma medication, previously failed surgical treatment, or a combination thereof

Exclusion Criteria:

• No light perception
• elevated IOP associated with silicone oil
• previous glaucoma drainage device implantation in the same eye
• previous cyclodestructive treatment
• increased risk of endophthalmitis (e.g., active adnexal and ocular surface infection, immunosuppression, or immunodeficiency, including the use of systemic steroids)
• posterior segment disorders, or pre-existing ocular comorbidities (e.g., pterygium, phacodonesis, corneal opacity, or corneal endothelial dystrophies).

Only 1 eye per patient was included in this trial.