Intravitreal Bevacizumab to Treat Retinopathy of Prematurity in 865 Eyes: a Study to Determine Predictors of Primary Treatment Failure and Recurrence

Abstract Purpose: This study aimed To evaluate the rate and risk factors for primary failure and recurrence after intravitreal anti-VEGF injection in retinopathy of prematurity (ROP).Methods: This retrospective study was performed on 865 eyes from 441 patients with retinopathy of prematurity receiving intravitreal Bevacizumab from 2012 to 2019. Medical records of patients were evaluated.Results: Mean gestational age (GA) and birth weight of patients were 28±2 weeks and 1121±312 g, respectively. Thirty-five eyes (4.04%) had a primary failure, including 18 eyes from 187 eyes in zone 1 (9.6%) and 17 eyes from 678 eyes in zone 2 (2.5%). The mean time of retreatment was 16.64±13.68 days in eyes without regression ROP. The remaining 830 eyes (95.95%) were included in recurrence analysis. The recurrence occurred in 33 eyes (3.97 %) of them in 20 patients, with the meantime of 77.52 days after the first treatment (IVB). Presence of plus disease, history of oxygen therapy or phototherapy, and GA less than 32 were associated with significantly increased prevalence of treatment failure. The risk factor predicting recurrence are lower birth weight, zone 1 pretreatment, history of intubation, anemia, and sepsis.Conclusion: Intravitreal anti-VEGF is a successful treatment for ROP with a low rate of primary failure and recurrence. Attention to risk factors accompanied by special care to patterns of treatment failure and recurrence helps to achieve early detection of treatment failure and vigilant follow up for recurrence.