Longitudinal studies of visual and cognitive development in young children with Down's syndrome

As part of a long-term study of visual and cognitive development in children with Down's syndrome, we are monitoring visual functions, including visual acuity, accommodation, refractive error, as well as scores on Bayley Scales of Infant Development in a cohort of 64 children throughout South and West Wales. Cross-sectional data, presented at a previous meeting, suggest a remarkable similarity between acuity and cognitive scores, in that both progress rapidly in the early months, and undergo a sudden rate change at the age of 2 years. We now have a sufficient longitudinal data to re-examine the progress of these two functions. Results for 12 children, each seen four times at similar ages, were analysed. Those children whose visual acuity falls outside the normal range at later ages, also show significantly lower cognitive scores, when compared to the children with normal visual acuity.