title: Alterations in the optic radiations of very preterm children-Perinatal predictors and relationships with visual outcomes.
abstract: Children born very preterm (VPT) are at risk for visual impairments, the main risk factors being retinopathy of prematurity and cerebral white matter injury, however these only partially account for visual impairments in VPT children. This study aimed to compare optic radiation microstructure and volume between VPT and term-born children, and to investigate associations between 1) perinatal variables and optic radiations; 2) optic radiations and visual function in VPT children. We hypothesized that optic radiation microstructure would be altered in VPT children, predicted by neonatal cerebral white matter abnormality and retinopathy of prematurity, and associated with visual impairments. 142 VPT children and 32 controls underwent diffusion-weighted magnetic resonance imaging at 7 years of age. Optic radiations were delineated using constrained spherical deconvolution tractography. Tract volume and average diffusion tensor values for the whole optic radiations and three sub-regions were compared between the VPT and control groups, and correlated with perinatal variables and 7-year visual outcome data. Total tract volumes and average diffusion values were similar between VPT and control groups. On regional analysis of the optic radiation, mean and radial diffusivity were higher within the middle sub-regions in VPT compared with control children. Neonatal white matter abnormalities and retinopathy of prematurity were associated with optic radiation diffusion values. Lower fractional anisotropy in the anterior sub-regions was associated with poor visual acuity and increased likelihood of other visual defects. This study presents evidence for microstructural alterations in the optic radiations of VPT children, which are largely predicted by white matter abnormality or severe retinopathy of prematurity, and may partially explain the higher rate of visual impairments in VPT children.
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Australia ; Florey Institute of Neuroscience and Mental Health, Melbourne, Australia.
authors.forename: Deanne K
authors.initials: DK
authors.lastname: Thompson
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Australia.
authors.forename: Dolly
authors.initials: D
authors.lastname: Thai
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Australia.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Kelly
authors.affiliation: Image Sciences Institute, University Medical Center Utrecht, The Netherlands.
authors.forename: Alexander
authors.initials: A
authors.lastname: Leemans
authors.affiliation: Florey Institute of Neuroscience and Mental Health, Melbourne, Australia.
authors.forename: Jacques-Donald
authors.initials: JD
authors.lastname: Tournier
authors.affiliation: Department of Medical Imaging, Royal Children's Hospital, Melbourne, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kean
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Australia ; Department of Paediatrics, The University of Melbourne, Melbourne, Australia.
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: St. Louis Children's Hospital, Washington University in St. Louis, St. Louis, USA.
authors.forename: Terrie E
authors.initials: TE
authors.lastname: Inder
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Australia ; Royal Women's Hospital, Melbourne, Australia ; Department of Obstetrics and Gynaecology, The University of Melbourne, Australia.
authors.forename: Lex W
authors.initials: LW
authors.lastname: Doyle
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Australia ; Department of Paediatrics, The University of Melbourne, Melbourne, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Anderson
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Australia ; Department of Paediatrics, The University of Melbourne, Melbourne, Australia ; Department of Neonatal Medicine, Royal Children's Hospital, Melbourne, Australia.
authors.forename: Rodney W
authors.initials: RW
authors.lastname: Hunt
mesh_terms: D016880:Anisotropy; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000503:physiopathology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009412:Nerve Fibers / Q000473:pathology; D009900:Optic Nerve / Q000473:pathology*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014786:Vision Disorders / Q000175:diagnosis* / Q000209:etiology
keywords: AD, Axial diffusivity; BWSDS, Birth weight standard deviation score; CI, Confidence interval; CSD, Constrained spherical deconvolution; Diffusion weighted imaging; FA, Fractional anisotropy; GA, Gestational age; MD, Mean diffusivity; MRI, Magnetic resonance imaging; Magnetic resonance imaging; Prematurity; RD, Radial diffusivity; ROP, Retinopathy of prematurity; Tractography; VPT, Very preterm; Visual system