To evaluate the effectiveness and safety of primary intravitreal ranibizumab injection as a treatment for retinopathy of prematurity.

Retrospective analysis of the medical records of patients diagnosed with retinopathy of prematurity and treated with intravitreal ranibizumab injection from January 1, 2013 to January 1, 2016 was performed. We complied with the standards for ‘prethresold, type 1’ established by the Early Treatment of Retinopathy of Prematurity study for intravitreal ranibizumab injection. The follow-up period after injection was at least 9 months. Patients who received additional treatment such as laser photocoagulation or intravitreal injection without reactivation of retinopathy of prematurity were excluded.

A total of 21 patients (39 eyes) were included in this study. Nine (16 eyes) were male and 12 (23 eyes) were female. The average duration between treatment decision and intravitreal ranibizumab injection was 2.1 ± 1.5 days. Complete regression of the plus sign occurred 18.2 ± 9.1days after injection. One eye with reactivation was treated with panretinal laser photocoagulation while four other eyes with reactivation were treated with intravitreal bevacizumab injection. There were 87.1% (34/39) eyes that underwent primary intravitreal ranibizumab injection with stable results without any reactivation. There were no systemic complications related to intravitreal ranibizumab injection.

Primary intravitreal ranibizumab injection as a treatment for retinopathy of prematurity showed good efficacy and safety. However, thorough evaluation is needed after primary intravitreal ranibizumab injection due to the potential for reactivation. Long-term monitoring is needed after intravitreal ranibizumab injection.