Long-term retinal vasculature abnormalities following intravitreal bevacizumab for retinopathy of prematurity

Purpose To report long-term fluorescein angiography (FA) findings in consecutive patients with type 1 retinopathy of prematurity (ROP) treated with intravitreal bevacizumab (IVB), whose ROP seemed to have resolved clinically. Methods Data were retrospectively collected for all patients with IVB-treated type 1 ROP who underwent an exam under anesthesia (EUA) and FA at 60 weeks post-gestational age (PGA) or older at a tertiary medical center between 2011 and 2020. FA results were reviewed for pathological vascular findings. Results Twenty-nine eyes of 16 patients were included. Mean gestational age and birth weight were 25.3 +/- 1.5 weeks and 762.2 +/- 189.8 g, respectively. The mean age at the time of EUA and FA was 23.4 +/- 15.8 months. All eyes had a peripheral avascular zone and irregular peripheral branching. Vascular loops were seen in 27 eyes (93.1%) and vascular bulbs and anastomoses in 16 eyes each (55.2%). Additional abnormal findings included leakage (10 eyes, 34.5%), vessels crossing the fovea (5 eyes, 17.2%), tortuous arteries and veins (9 eyes, 31%, and 5 eyes, 17.2%, respectively), and neovascularization (2 eyes, 6.9%). When comparing patients who were less than or greater than 70 weeks PGA at follow-up, FA findings in the group with shorter follow-up were significant for more anastomoses and vascular bulbs (p = 0.002 and p = 0.024, respectively) and trended towards more leakage (45.5% vs. 27.8%, p = 0.331). Conclusion The vast majority of IVB-treated type 1 ROP eyes suffered from vascular pathologies long after treatment. There may be long-term progression in the vascularization process of the retina in some cases.