Retinopathy of prematurity (ROP) is a proliferative retinopathy of immature or low birth weight infants. Its prevalence is about 15-30% in preterm infants, and almost all patients are preterm low birth weight infants. Etiology: In normal fetuses, there is significant retinal vascular proliferation at 6 to 7 months. It reaches the nasal serrated edge (grows all over the retina) at about 36 weeks (August). Retinal vessels are not fully developed in preterm infants and continue to develop after birth. At the periphery, especially near the temporal serrated edge, there is still an avascular zone. The tissue at the front of the developing vessels has not yet differentiated into capillaries, and these tissues are very sensitive to oxygen. If the infant inhales high concentrations of oxygen, it is likely to cause vascular atresia and inhibit the formation of additional blood vessels. Prematurity, low birth weight and oxygen administration are risk factors for the development of ROP. Clinical presentation: Most children are identified during screening and receive prompt treatment. When parents find abnormal visual acuity or pupils, the lesions are usually advanced and the prognosis is relatively poor. Ultrasound: It can determine whether retinal detachment has occurred in the fundus and the type and degree of retinal detachment, and whether there is occupational disease. 2.Retcam pediatric fundus camera: used for screening children with ROP and collecting fundus examination image data. It provides a basis for laser treatment and post-surgical follow-up. It can also be used for fluorescence angiography of the fundus in children with ROP. Screening, treatment, and follow-up The screening criteria for ROP established by the National Academy of Pediatrics and the American Academy of Ophthalmology are birth weight <1500 and gestational age <28 weeks for preterm infants; for preterm infants with unstable systemic conditions, the screening criteria are relaxed to 1500-2000 g. The first examination should be performed at 4-6 weeks after birth, or at 31 weeks of corrected gestational age. In China, the screening criteria for ROP are relaxed to weight < 2000g and gestational age < 32 weeks; even to 2200g and gestational age < 34 weeks for preterm infants with high risk factors. There are no clinically available drugs that can safely and effectively control the course of ROP. In the progressive stage of the lesion, depending on the lesion, laser, condensation or scleral buckling, vitrectomy is chosen. 1.ROP stage 1 to 2: Since about 85% of cases can regress naturally, there is no need for special treatment and only regular observation. 2.ROP stage 3: Once a child with stage 3 progresses to the threshold lesion, i.e., retinal lesions exceeding 5 consecutive clock points or accumulating 8 clock points, combined with Plus disease, laser photocoagulation or condensation treatment should be performed within 72h. The current mainstream treatment uses laser to treat threshold and pre-threshold ROP. 3. Stage 4-5 ROP: For patients with stage 4, partial retinal detachment is treated with scleral buckling surgery or vitrectomy with preservation of the lens. For this part of children with retinal repositioning as the treatment purpose, vision is basically absent or very low. Early detection and early treatment of ROP is the fundamental way to save the vision of children with ROP. The importance of retinal screening in preterm infants is emphasized. Prevention 1. Prevention of prematurity 2. Reasonable use of oxygen in preterm infants 3. Retinopathy of prematurity screening China's guidelines for the prevention and treatment of retinopathy of prematurity stipulate that fundus screening for preterm and low birth weight infants with birth weight < 2000g should be started at 4-6w after birth or corrected gestational age 32w until peripheral retinal vascularization. Screening may be expanded appropriately for preterm infants with severe disease.