The purpose of this study is to compare the efficacy (times of injection, change of visual acuity and Cva/ I) and safety (macular visual function and choroidal thickness) of different dosing of ranibizumab intravitreal injection (1+PRN vs. 3+PRN) in treating with pathological myopia choroidal neovascularization (PM-CNV).

PM is a common disease in east asia, while PM-CNV affect 5%-10% PM patients.PM-CNV has specific characteristics, including small dimensions and limited exudative manifestations comparing with age-related macular degeneration. However, treatment regimen and re-treatment criteria follow the PrONTO protocol. The question of the optimal dose and treatment regimen in myopic CNV management is still unresolved. There is no unequivocal evidence suggesting hat PRN treatment is more effective than a loading phase followed by an as-needed variable dosage regimen.

Inclusion Criteria:

• older then 18 years old
• refractive error ≥ -6.0 diopters or axial length ≥ 26.0mm
• active CNV due to high myopic which is the only reason cause visual loss confirmed by fluorescein fundus angiography
• BCVA ≥ 24.0 and ≤73 letters at a starting distance of 4 meters using Early Treatment Diabetic Retinopathy Study visual acuity chart.

Exclusion Criteria:

• history of (a) stroke,(b) laser photocoagulation involved macular area in study eye, (c) intraocular treatment with corticosteroids or intraocular surgery or anti vascular endothelial growth factor or verteporfin photodynamic therapy within 6 months in study eye, or (d) hypersensitivity to ranibizumab or fluorescein
• presence of active infectious disease or confirmed intraocular pressure ≥ 21.0 mmHg
• pregnant or nursing women
• uncontrolled high blood pressure ≥ 150/90 mmHg or uncontrolled fasting blood glucose ≥ 7 mmol/L