Retinopathy of prematurity (ROP), formerly known as posterior lens fibroplasia, is a blinding retinal disease that occurs mainly in premature, low birth weight infants. In recent years, with the vigorous development of neonatal medicine in China, the survival rate of preterm infants has increased significantly and the incidence of ROP has shown a gradual increase, which has become a major factor of childhood blindness in China and deserves high attention. ROP is curable, and more than 90% of children with ROP can preserve their vision through treatment, provided that they are actively screened for early detection. At present, the cure rate of ROP in developed countries has reached more than 95%, and only a few hundred children are blinded by ROP each year in the United States, whose incidence rate is only one percent of that in China. Therefore, how to catch up with the level of ROP prevention and treatment in developed countries in the world is a major issue concerning the overall survival quality of premature babies in China and the harmony and stability of social families, which requires the common attention of medical workers and parents of premature babies and even the whole society. Why does ROP occur in premature babies? If we compare the eye to a camera, the retina is like a photographic negative. Premature babies are actually equivalent to embryos that are separated from their mothers in advance, at this time their eye structure is not yet well developed, and the development of retinal blood vessels in the fundus is not mature. After separation from the mother, due to the difference between the external environment and the intrauterine environment, especially the difference in retinal oxygen content, the development of retinal vessels may be abnormal, resulting in the proliferation of neovascularization, leading to the formation of retinopathy, which may progress to retinal detachment and eventually blindness if timely intervention is not made. Full-term babies do not develop this disease because the retinal blood vessels are already developed. What is the risk of ROP in premature babies? Retinopathy of prematurity is predominantly seen in preterm infants less than 32 weeks of gestational age and weighing less than 1,600 g. The incidence varies from country to country. In the United States, the multicenter ROP study group investigated 4099 cases of preterm infants with birth weight less than 1251g, 65.8% of them had ROP, 81.6% of 2237 cases with birth weight less than 1000g, and 68.5% of 3821 cases of preterm infants with gestational age less than 32 weeks had ROP. In China, Guo Yizhen reported that ROP occurred in 40% of 149 very low birth weight infants and 86% of preterm infants between 500 and 750 g. Luo Liang reported that the incidence of ROP in preterm infants was 21.6%. The prevalence of ROP among 1675 preterm infants was reported by Bayi Children’s Hospital to be 11.6%. In general, it seems that the lower the birth weight and the younger the gestational age, the higher the incidence of ROP. What kind of preterm babies are prone to ROP? Current research shows that the etiology of ROP is multifactorial, with low birth weight and gestational age being the most important factors. Other risk factors such as oxygenation, candidemia, intraventricular hemorrhage, ductus arteriosus, dopamine application, light exposure, blood transfusion, vitamin E deficiency, ethnicity, steroid hormone application, etc. In general, the smaller the gestational age and weight, the more severe the condition and the more complications, the more likely the preterm infant is to develop ROP. Fourth, is ROP purely caused by oxygen intake? Due to the one-sided propaganda of the media, many parents think that ROP in preterm babies is caused by oxygen intake. Inhalation of high concentrations of oxygen was once thought to be the main factor causing ROP, but it was not until the 1960s that this view was corrected, with relative tissue hypoxia being the key factor. Tissue relative hypoxia can be converted into oxygen radicals in the body through a series of reactions, causing toxic damage to enzymes, lipoproteins, etc. The defective antioxidant system in preterm infants prevents the simultaneous detoxification of antioxidant defense mechanisms in tissues, thus causing tissue damage and stimulating neovascularization. Since oxygen therapy is not only related to ROP, but also closely related to the development of the nervous system of preterm babies, the correct and reasonable oxygen therapy is the key to protect the healthy growth of preterm babies. V. How to avoid blindness caused by ROP in preterm babies? If ROP develops to a certain extent, retinal detachment and eventual blindness will occur. To avoid this serious consequence, the key lies in timely screening and treatment. Internationally, all preterm infants with birth weight less than 1500 grams or gestational age less than 32 weeks, regardless of whether they have been on oxygen or not, are included in the screening process, and those with birth weight between 1500-2000 grams or gestational age between 32-34 weeks, who have been on oxygen or have severe comorbidities, are also included in the screening process. In recent years, some cases of ROP blindness have occurred in China with a birth weight of 1700-2000 g. The Ministry of Health of China has defined the indications for ROP screening as: preterm and low birth weight infants with a birth weight of less than 2000 g. This means that all preterm and low birth weight infants with a birth weight of less than 2000 g are included as screening subjects. For those with a birth weight of 2000g or more, and with high risk factors such as oxygenation and sickness, screening should also be performed when available. The first screening is usually performed at 4-6 weeks after birth or at 32-34 weeks of corrected gestational age. Thereafter, the frequency of review is determined according to the results of the first screening: ① if there are no lesions or only stage I lesions in both eyes, review every other week until the retinal vessels grow to the serrated edge; ② if there are stage II lesions or pre-threshold lesions or Rush lesions, review once a week until the lesions are completely regressed; ③ if there are stage III lesions, review 2-3 times a week; ④ if the threshold level is reached, within 72 hours after diagnosis laser treatment was performed. This will ensure that children with threshold ROP are treated in a timely manner, while reducing the number of unnecessary examinations and ensuring that a high screening effectiveness is maintained. What are the means of fundus screening for babies? The current means of fundus screening include direct fundoscopy, indirect fundoscopy and RET-CAM fundus camera. Direct fundoscopy has been eliminated because of its narrow field of view and low resolution, and the RetCam digital retinal camera can observe and accurately record the retinal images of infants and children, but the equipment is more expensive and only a few dozen units are available worldwide. It is equipped with a ROP lens with a viewing angle of 130 degrees, which can overcome many of the shortcomings of traditional binocular indirect fundoscopy and can be used for ROP screening and diagnosis with the advantages of simple operation, easy to master, short time required, small stimulation, wide visual range, high resolution, accurate recording, and no corneal complications. It is a revolution in fundus screening, as the data of the child can be saved for continuous observation and remote consultation. How to treat my baby with ROP? The treatment methods for ROP include laser, condensation, medication and vitrectomy, scleral ring ligation, etc. Laser surgery is currently the best treatment for ROP, with the advantages of direct targeting of the diseased retina, accurate positioning, low incidence of intraocular hemorrhage, simple treatment process, less damage to the choroidal retina, and low incidence of postoperative myopia and astigmatism. Its treatment success rate has reached about 95%. There are two types of lasers: argon ion (Ar) laser and diode laser. Argon ion (Ar) laser is blue-green light, easy to be absorbed by other structures of the eye and cause serious complications, such as corneal clouding, postoperative cataract. The diode laser is red or infrared light, which is highly penetrating and not easily absorbed by the refractive interstitium, and has fewer complications. Complications of laser treatment for ROP include corneal and iris thermal injury, iris atrophy, lens clouding, low intraocular pressure, glaucoma, neovascularization, and secondary cataract. If the progression of the lesion is not controlled by laser treatment, anti-VEGF antibody vitreous injection or vitrectomy may be performed. Our advantages in the prevention and treatment of ROP in preterm infants Our hospital is one of the first units in China to pay attention to the prevention and treatment of ROP, and has invested heavily in the international most advanced Ret-Cam 2 fundus imaging system and French 532nm and 830nm fundus laser therapy instruments. The Ret-Cam 2 fundus imaging system has the advantages of fast, wide angle, data retention and high diagnostic rate, and has been used to screen over 10,000 preterm babies without any missed cases. We are also the first in China to develop bedside ROP laser treatment technology that relies on NICU monitoring conditions, with a minimum weight of 800g at the time of treatment, effectively ensuring timely and safe treatment. At present, only one hundred cases of ROP treatment for premature infants have been completed, with a success rate of over 95% and no case of blindness. It is the only unit in Beijing that can carry out ROP treatment at the bedside in NICU. In the special flight inspection of oxygen and ROP prevention and treatment for premature infants organized by the Ministry of Health in 2010, our hospital was ranked first among 16 famous NICUs in China, indicating that the level of ROP prevention and treatment for premature infants in our hospital has reached the leading level in China. CCTV, Beijing TV, Qilu TV and many other news media have widely reported on the deeds of our department. We will protect the bright future of premature babies with our exquisite technology and enthusiastic service.