Accommodative Dysfunction and Refractive Anomalies in Children with Cerebral Palsy (CP)

Abstract

Abstract: : Purpose:To determine the prevalence, nature and degree of refractive errors and accommodative dysfunction among children with different types and severities of cerebral palsy (CP) in Northern Ireland. Methods: 95 subjects with CP (aged 4–15 years) were recruited via the Northern Ireland CP Register (NICPR). Objective measurements of visual status were performed on each child including visual acuity assessment (preferential looking), accommodation (dynamic retinoscopy) and refractive error (under cycloplegia). Refractive error was classified as clinically significant in the following cases: hyperopia > +3.00D in any meridian, myopia > –0.50D, anisometropia and/or astigmatism > 0.75D. Dynamic retinoscopy was used to measure lag/lead of accommodation at three test distances: 25cm (4D), 16.7cm (6D) and 10cm (10D). Each subject's neurological status was derived from the NICPR. Refractive error and accommodative function were also assessed in an age–matched control group (n=128) for comparison. The control group were neurologically and visually normal children recruited from a local primary and secondary school. Results: Subjects with CP had a significantly increased incidence of clinically significant refractive errors(37%) compared to the control group (15.6%) (Chi–square p=0.001). 51.5% of subjects with CP demonstrated reduced accommodation (accommodative lag outside normal limits at one or more distance). Compared to those with spastic CP children with ataxic or dyskinetic CP were at a significantly increased risk of accommodative dysfunction and more hypermetropic refractive errors (ANOVA p<0.05 and p<0.05 respectively). Reduced accommodative responses were significantly associated with more severe motor and intellectual impairments (ANOVA p=0.00, p<0.01 respectively). Conclusions: Brain injury such as that present in CP has a significant impact on refractive development and accommodative function. The type and site of brain injury differentially affect refractive status and accommodative function. These findings have implications for the Optometric care of children with CP and inform our understanding of the role of different areas of the brain in visual development.

Keywords: refractive error development • visual development: infancy and childhood • clinical (human) or epidemiologic studies: prevalence/incidence