Definition Retinopathy of prematurity is a proliferative retinopathy in immature or low birth weight infants. The retinal vasculature is not fully developed in preterm infants, and ischemia and hypoxia in the postnatal retina can induce abnormal retinal neovascularization, resulting in proliferative retinopathy and retinal detachment, which can be complicated by strabismus, amblyopia, cataract, or secondary glaucoma at a later stage. Staging Retinopathy of prematurity is divided into 5 stages: Stage 1: A line of demarcation appears between the vascular and avascular areas in the peripheral retina of the eye. Stage 2: The line of demarcation is elevated and shows crest-like changes. Stage 3: Dilated retinal vessels proliferate on the crest, which may be accompanied by proliferation of fibrous tissue. Stage 4: Tractional retinal detachment occurs due to fibrovascular proliferation, and this stage is divided into stage A and B according to whether there is macular detachment or not. stage A has no macular detachment, and stage B has macular detachment. Stage 5: Total detachment of the retina occurs. PLUS lesion refers to dilated and tortuous retinal blood vessels in the posterior pole, indicating that the lesion will progress rapidly and needs to be closely observed. Screening criteria Fundus screening is started for preterm and low birth weight infants with birth weight less than 2000g. The scope of screening can be expanded for preterm infants with serious diseases. The first screening should be started at 4 to 6 weeks after birth or 32 weeks of corrected gestational age. This article is published with permission from Dr. Jing Huang.