Recurrence of retinopathy of prematurity after intravitreal ranibizumab monotherapy: Timing and risk factors

Abstract

Purpose. To investigate timing and risk factors of recurrent retinopathy of prematurity (ROP) after intravitreal ranibizumab (IVR) monotherapy. Methods. Fifty eyes (the more severe eye) of 50 infants treated with IVR monotherapy for type 1 ROP were studied retrospectively. The mean follow-up time was 31 weeks after IVR. Recurrent ROP (recurrence of extraretinal fibrovascular proliferation [EFP]) was determined by RetCam wide-angle fundus imaging and binocular indirect ophthalmoscopy. Risk time of recurrence was estimated by Kaplan-Meier survival analysis with recurrence as the endpoint. Time-varying recurrence hazard rate was determined using the hazard function of life-table analysis. The risk factors of recurrence were explored by logistic regression analysis. Results. Recurrence of ROP occurred in 32 (64%) of 50 eyes at 7.9 ± 2.7 weeks after IVR. Most of recurrence (94%) occurred in 2.5 to 12.0 weeks following IVR treatment. The recurrence hazard rate reached its maximum at 8 weeks. Recurrence affecting the initial site of EFP occurred significantly earlier than recurrence only at the new vascular advancing edge (4.5 ± 1.4 weeks versus 9.1 ± 2.0 weeks after IVR, P < 0.001). The independent risk factors of recurrence included extensive retinal neovascularization (P = 0.005) and oxygen requirement after IVR (P = 0.016). Conclusions. Recurrence of type 1 ROP should be carefully watched in a long-term follow-up after IVR monotherapy, particularly in the first 12 weeks after IVR and for those with extensive retinal neovascularization or prolonged oxygen therapy.