Retinal Vascularization Timeline following Intravitreal Bevacizumab Injection in Infants with Retinopathy of Prematurity: A Retrospective Study.

Abstract

Purpose: To investigate the timeline of retinal vascularization and associated risk factors in infants with retinopathy of prematurity (ROP) treated with intravitreal bevacizumab (IVB).

Methods: This retrospective cohort study was conducted at the ROP clinic of the Khatam Eye Hospital from 2014 to 2023. The study included preterm infants diagnosed with ROP who received IVB injection. The primary outcome measure was the time to complete retinal vascularization, defined as the number of weeks from the IVB injection to the point when vascularization extended to the ora serrata.

Results: The study population comprised 155 (49.7%) female and 157 (50.3%) male neonates. The average gestational age at birth was 28.83 weeks (±2.228), and the average birth weight was 1244.90 g (±406.291). The mean duration of hospitalization in the neonatal intensive care unit was 33.71 days (±18.193). The mean (standard deviation) age and weight at complete retinal vascularization were 60.92 (15.16) weeks and 6064.01 (1616.87) g, respectively. The mean time interval between IVB injection and complete retinal vascularization was 24.31 (13.64) weeks. Survival analysis revealed that infants born before 30 weeks or weighing <1500 g experienced longer durations to full vascularization (P < 0.001). In multivariate Cox regression analysis, none of the variables were identified as independent risk factors for the time to complete vascularization.

Conclusions: This study investigated the duration required for complete retinal vascularization in infants with ROP who received IVB injections. In addition, it evaluated the influences of birth weight, age, and gender as critical factors affecting the time to complete vascularization.