Visual development in infants and young children with Down's syndrome

Abstract

Purpose: Ocular and refractive defects are common amongst people with Down's syndrome. We are conducting a long‐term study of the development of refraction, accommodation and acuity in infants with Down's syndrome, from 12 weeks of age, in order to identify age of onset and possible consequences of such defects. Methods: To date, 54 children have entered the study. All measurements are made during home visits, and comprise Mohindra and dynamic retinoscopy, and Preferential Looking. Results: Cross‐sectional data suggest that acuity lies within normal ranges in infancy, and falls behind the norms only from the age of 2 years. Refractive errors in the general population decrease in infancy (the process of emmetropisation). Our data show that the opposite happens in children with Down's syndrome. The prevalence of refractive errors is higher in the preschool and school‐age children, than amongst the infants. Accommodation is defective from the earliest age of testing. Infants and young children with Down's syndrome consistently under‐accommodate to near targets, even when visual acuity and refractive errors are normal. Conclusions: The implication of accommodative dysfunction on emmetropisation is considered, and the possible association between visual and cognitive development explored.