Effects of Different Dosages of intravitreal Bevacizumab (Avastin) for Neovascular Age-related Macular Degeneration: a Randomized Controlled Trial

INTERVENTION: Two groups:1.25mg intravitreal bevacizumab at monthly interval 3 to 6 months versus 2.5mg intravitreal bevacizumab; CONDITION: Neovascular age‐related macular degeneration PRIMARY OUTCOME: Best‐corrected visual acuity at 6 month; SECONDARY OUTCOME: . Retinal thickness measured by optical coherent tomography (OCT) at each visit ii. Proportion of patients with moderate visual loss at 6 months iii. Proportion of patients with stable or gain in vision at 6 months iv. Intraocular pressure measured by non‐contact tonometry (NCT) at each visit v. Changes in macular function as measured by multifocal electroretinography (mfERG) at each visit vi. Changes in fluorescein angiography at 6 months vii. Change in levels of aqueous VEGF, PEDF and other g;1. Retinal thickness measured by optical coherent tomography (OCT) at each visit;2. Proportion of patients with moderate visual loss at 6 months;3. Proportion of patients with stable or gain in vision at 6 months;4. Intraocular pressure measured by non‐contact tonometry (NCT) at each visit;5. Changes in macular function as measured by multifocal electroretinography (mfERG) at each visit;6. Changes in fluorescein angiography at 6 months;7. Change in levels of aqueous VEGF, PEDF and other growth factors / cytokines during the study period; INCLUSION CRITERIA: INCLUSION CRITERIA: 1. Aged 50 years or older; 2. Subfoveal CNV within the foveal avascular zone due to AMD; 3. Patients with best‐corrected visual acuity of better than 1.3 ETDRS logMAR units; 4. Patients physically fit to receive intravitreal injection; 5. Informed consent.