Comparison of Clinical Outcomes of Intravitreal Bevacizumab and Aflibercept in Type 1 Prethreshold Retinopathy of Prematurity in Posterior Zone II

Purpose: To evaluate the efficacy and safety of intravitreal injection (IVI) of bevacizumab (IVB) versus aflibercept (IVA) in premature infants with type 1 prethreshold retinopathy of prematurity (ROP) in the posterior Zone II. Methods: The study was a multicenter, historical cohort of premature newborns diagnosed with type 1 prethreshold ROP in the posterior Zone II, treated with IVB or IVA. Demographic features, complications, and treatment outcomes were then compared between the two groups. Results: Seventy-six patients received aflibercept (the IVA group), and 210 received bevacizumab (the IVB group). The two groups were not significantly different in terms of postmenstrual age (PMA) at the time of ROP diagnosis and other known risk factors for ROP development and progression. All eyes in both the groups responded to IVI; however, recurrence was observed in four eyes (1.9%) in the IVB group and 12 (15.8%) in the IVA group (P = 0.001). Recurrence occurred 9.1 +/- 0.83 (5-12) and 15.5 +/- 0.98 (12-18) weeks after primary treatment in the IVB and IVA groups, respectively (P = 0.000). In the IVA group, retinal vascularization was completed in 38.18 +/- 6.5 weeks (21-48) after IVI, and it happened in 23.86 +/- 9.3 weeks (13-60) in the IVB group (P = 0.009). Furthermore, vascularization reached the peripheral retina in 73.25 +/- 6.5 (56-84) and 58.75 +/- 8.8 (45-93) weeks, PMA in the IVA and IVB groups, respectively (P = 0.03). No acute postoperative complications were observed in the treated eyes in either group. Conclusion: This study shows that both IVA and IVB are effective and well tolerated for the management of type 1 prethreshold ROP in the posterior Zone II; however, IVA needs a significantly longer time for vascularization completion and has a higher recurrence rate compared with IVB.