This was a multicenter, open-label extension study where the Visual Acuity (VA) assessment at the child's 5th birthday visit was performed. The study had 2 distinct periods (Epochs). Treatment with study ranibizumab (either as retreatment after ranibizumab had already been injected in the same eye or as switch ranibizumab treatment from study laser therapy administered in the core study) was permitted for eligible eyes with recurrence/worsening of ROP up to and including Week 40 from the baseline visit in the core study (Epoch 1). The remainder of the extension study up to the 5th birthday visit (Epoch 2) was observational, with no study treatment planned to be administered.
In the core study, patients were randomized to 1 of the 3 treatment arms (ranibizumab 0.2 mg, ranibizumab 0.1 mg, and laser). Treatment arm assignment and patient identifier in the extension study remained the same as in the core study.
