Visual outcomes and perinatal adversity Anna R. O’Connor a, *, Alistair R. Fielder b a University of Liverpool, Division of Orthoptics, Thompson Yates Building, Quadrangle, Brownlow Hill, Liverpool, L69 3GB, UK b City University, London, UK KEYWORDS Retinopathy of prematurity; Strabismus; Refractive error; Visual acuity; Low birth weight; Cerebral visual impairment Summary Preterm birth per se, the neonatal environment, retinopathy of prematurity (ROP) and neurological damage are all causes of visual impairment and the impact of these factors is discussed in relation to the resultant ophthalmic deficits. Visual acuity impairments range from blindness, due to ROP or cortical visual impairment, which can be identified at an early age, to subtle deficits related to preterm birth only identified at a later age. Visual function deficits are not limited to visual acuity but can affect contrast sensitivity, field of vision and colour vi- sion. Strabismus and refractive errors are also very common in children following perinatal ad- versity. Although more is now known about the types of deficits affecting these children, there is still a poor understanding of how these deficits impact on a child’s functional ability. The impact of these ophthalmic deficits on the long term ophthalmic care required, and the role of perinatal factors, is discussed. ª 2007 Elsevier Ltd. All rights reserved. Introduction Events in the perinatal period are major contributors to visual impairment in childhood occurring in children who have been born preterm or at full term. However, despite an increase in the survival rates of extremely low birth weight (ELBW) babies over the last three decades or so there has been an encouraging reduction in the rate of neurosensory disability, including blindness. 1,2 Neverthe- less, the risk of severe visual disability for babies of birth weight <1500 g is increased by over 25 times compared to children born at full term. 3 To gain a sense of proportion, it is important to note that most children born prematurely achieve vision within normal limits so that the incidence of visual acuity of less than 6/60 is about 0.8% at 3.5 years. 4 The adverse visual outcomes following perinatal adver- sity fall into a wide clinical spectrum that ranges from blindness and severe visual disability to less severe impair- ments, some of which are extremely subtle. What consti- tutes adversity to the visual pathway can be considered under four main aetiological headings: preterm birth per se, the neonatal environment, retinopathy of prematurity (ROP) and neurological damage. Teasing out the individual contribution of each of these four factors to overall out- come is sometimes relatively straightforward, but in many instances is quite impossible. Consequently, here we will not attempt to differentiate but will structure the review mainly on the functional outcomes rather than aetiological categories. Outcomes will be presented, where possible, as outcomes in the neonatal period, early childhood and long term. First, a few introductory words on the major aetio- logical categories are required before considering how oph- thalmic outcome is affected. * Corresponding author. E-mail address: annaoc@liv.ac.uk (A.R. O’Connor). 1744-165X/$ - see front matter ª 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.siny.2007.07.001 available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/siny Seminars in Fetal & Neonatal Medicine (2007) 12, 408e414