Martínez-Castellanos MA, et al. - Researchers conducted this retrospective chart review to present a diagnostic algorithm of recurrence [defined as the new appearance of plus disease, an elevated ridge, or pathological new vessels following an initial regression of ROP following treatment] and treatment failure [defined as persistence or progression of neovascularization, elevation of the ridge, worsening of plus disease, or retinal crunch within the first week after treatment] following intravitreal bevacizumab (IVB) injection for retinopathy of prematurity type 1 (ROP1) and the stepwise therapeutic approach for both conditions. The sample consisted of all individuals diagnosed with ROP1 initially treated with IVB in six tertiary referral centers of Toluca and Mexico City from 2005 to 2017. In total, 672 patients who received intravitreal bevacizumab injection for ROP1 treatment were involved. Intravitreal injection of anti-VEGFs to treat ROP requires close follow-up as some of these patients may experience treatment failure or disease recurrence. Differentiating between them is important for preventing misdiagnosis and providing the right treatment. A novel algorithm was proposed for the follow-up and treatment approach of ROP1 following initial treatment with IVB. This algorithm summarizes the recommendations based on a large case series of patients with ROP1. As more clinical evidence is available, it is meant to grow and expand.