Visuopathy of prematurity: Brain MRI alterations, neurodevelopment, and visual outcomes in children and adults born preterm

Abstract

Being born preterm increases the risk of long-term neurodevelopmental challenges and adverse visual outcomes, such as reduced visual function. The adverse outcomes seem to be present even without cerebral damage or severe eye disease, such as retinopathy of prematurity (ROP), characterized by abnormal blood vessel growth in the retina, causing reduced vision. Therefore, ROP might just be the tip of an iceberg of a larger entity termed «Visuopathy of prematurity» (VOP) which may involve brain alterations and altered retinal structure that could explain the adverse visual outcomes in individuals born preterm. In this thesis, we aimed to assess brain matter, neurodevelopment, and visual outcomes in school-aged children born extremely preterm (gestational age ≤28 weeks) and adults born preterm with very low birth weight (VLBW; birth weight ≤1500 g) in Central Norway. We also aimed to explore whether imaging of retinal structure and brain matter microstructure along the visual pathway could reveal potential clinical imaging markers for adverse visual outcomes. Visual function was examined in the clinic, retinal structure and brain matter microstructure was assessed by imaging, and visual pathway function was recorded with electrophysiology. Also, we assessed neurodevelopmental challenges at school age with parent reports and neuropsychological testing. We found an altered retinal structure in children born preterm and reduced visual function associated with a higher level of neurodevelopmental challenges within motor skills, learning, perception, and executive functions at school age. We also found altered retinal structure and reduced visual function in VLBW adults compared to a control group of adults born to term. Moreover, VLBW adults displayed brain matter alterations along the visual pathway that predicted reduced visual function. The findings of this thesis suggest that a multi-disciplinary approach using both clinical imaging markers and visual function testing could provide a more comprehensive understanding of the mechanisms underlying adverse visual outcomes in children and adults born preterm. In addition, a multi-disciplinary approach might contribute to identifying the cause and extent of the adverse visual outcomes, thereby improving the follow-up of individuals born preterm.