disease can result in serious vision impairment and consequently all babies at risk of sight-threatening ROP should be screened. This evidence-based guideline for the screening and treatment of ROP was developed by a multidisciplinary guideline development group (GDG) of the Royal College of Paediatrics & Child Health (RCPCH) in collaboration with the Royal College of Ophthalmologists (RCOphth), British Association of Perinatal Medicine (BAPM) and the premature baby charity BLISS. The guideline was produced according to RCPCH standards for guideline development.1 The guideline provides 25 evidence-based recommendations and 21 good practice points. Recommendations are graded A-D using SIGN grading hierarchy,2 according to the strength of the evidence underpinning them. The good practice points (GPP) are a consensus of the GDG. This Executive Summary highlights those recommendations and good practice points considered by the GDG to be priorities for implementation. This guideline has been produced specifically for use within the UK and supersedes the previous guideline.3 It will not be applicable in countries where more mature babies are at risk of sight threatening ROP.4 Not all the recommendations are included in this Summary. The full Guideline should be consulted which also contains complete details of the Guideline methodology. Appendices A, B, C and D give a standardised sheet for recording screening results, an algorithm for ophthalmic criteria for screening and treatment, the International Classification of ROP Revisited, and parent information leaflets respectively. All the documents are available on the websites of the Royal College of Ophthalmologists www.rcophth.ac.uk, the Royal College of Paediatrics and Child Health www. rcpch.ac.uk/ROP or the British Association of Perinatal Medicine www.bapm.org. The guideline will be updated within five years of its publication date. UK Retinopathy of Prematurity Guideline – May 2008 iv Key Recommendations/Good Practice Points for Implementation Screening Criteria • All babies less than 32 weeks gestational age (up to 31 weeks and 6 days) or less than 1501g birthweight should be screened for ROP. One criterion to be met for inclusion. GPP • All babies less than 31 weeks gestational age (up to 30 weeks and 6 days) or less than 1251g birthweight must be screened for ROP. One criterion to be met for inclusion. B Screening Protocol • Babies born before 27 weeks gestational age (i.e. up to 26 weeks and 6 days) - the first ROP screening examination should be undertaken at 30 to 31 weeks postmenstrual age B • Babies born between 27 and 32 weeks gestational age (i.e. up to 31 weeks and 6 days) - the first ROP screening examination should be undertaken between 4 to 5 weeks (i.e. 28-35 days) postnatal age. B • Babies >32 weeks gestational age but with birthweight. Retinopathy of prematurity (ROP) is a vasoproliferative retinal disorder unique to premature infants. As premature births increase in many areas of the world, ROP has become a leading cause of childhood blindness. A better understanding of the pathogenesis of ROP, adherence to strict screening guidelines, and evolution of treatment options have reduced the number of sight-threatening complications from ROP. Retinopathy of prematurity (ROP) is a disorder of retinal blood vessel development in low birth weight preterm infants and is the second leading cause of childhood blindness in the United States behind cortical visual impairment [1]. ROP is a complex disease process initiated in part by a lack of complete retinal vascularization in premature infants. Retinal vascular development begins during week 16 of gestation, proceeding from the optic disc centrifugally to the retinal periphery. In almost all term infants, the retina and retinal vasculature are fully developed, and ROP cannot occur. However, in preterm infants, the development of the retina is incomplete. The degree of retinal immaturity depends on the degree of prematurity at birth. The absence of retinal vessels in the immature retina can result in retinal ischemia, leading to the release of vascular growth factors [2]. Earlier stages of the disease may regress spontaneously at any time. If the disease progresses, vitreous hemorrhage, tractional retinal detachment, and blindness can occur [3]. ROP was initially described by T. L. Terry as retrolental fibroplasia (RLF) in 1942 when he noted a dense, white, fibrovascular plaque behind the lens in a series of preterm infants [4]. This finding was eventually understood to be a complete tractional retinal detachment, which is the end stage of this disease. In the 1950s, RLF became the leading cause of infant blindness in developed countries with organized and well-funded health care. It was suggested that oxygen toxicity caused the disease, as babies born prematurely in developed countries were treated in incubators with artificially high levels of oxygen [5]. The incidence of ROP decreased in the 1960s with limitation of oxygen for preterm infants. Unfortunately, this also led to an increase in preterm infant deaths and cerebral palsy [6]. Epidemiology and Risk Factors Each year in the United States, about 14,000 preterm infants are affected by ROP. Of these infants, approximately 90% experience spontaneous regression, and between 1,100 and 1,500 develop disease severe enough to require medical treatment [7]. The Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) Cooperative Group determined that ROP occurred in 66% of infants with a birth weight of 1,250 g or less and in 82% of infants with a birth weight of less than 1,000 g [3]. Despite appropriate medical interventions, 400 to 600 infants each year in the United States become legally blind from ROP [7]. Gestational age and birth weight, the two greatest risk factors for ROP, are inversely correlated with the development of ROP. Specifically, smaller babies and those born at an earlier gestational age are at higher risk. Between 1986 and 2013, the birth weight and gestational age of infants enrolled in ROP studies in the United States decreased, whereas ROP prevalence and incidence remained stable [8]. In regions of the world where