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.