To evaluate and compare two individualised ranibizumab treatment regimens, differentiated by the definition of disease activity which determines the treatment interval until the next injection. The results will be used to generate further recommendations about intensive versus relaxed treatment approaches and how they can be utilised within an 'inject and extend' approach to maximise patient outcomes, while reducing the need for potentially unnecessary intravitreal injections. This study will also investigate genotypic expression and response to intravitreal injections of ranibizumab between the two treatment arms.