Eye movement dysfunction vs. language delays in migrant children.
The Developmental Eye Movement Test (DEM) is a popular visual-verbal saccade test. An advantage of the DEM is that patients with below-average verbalization or automaticity can be distinguished from patients with eye movement coordination problems. The standardized norms for the DEM were previously determined in a sample of suburban and urban children with expected age to grade levels. We hypothesize that language difficulties common in some minority groups would be reflected by subnormal DEM automaticity but not eye movement dysfunction. A group of children in the U.S. Department of Education's Massachusetts Migrant Summer Education Program were prospectively studied with the DEM. The sample included 84 subjects (age 7-12) from various ethnic and educational backgrounds. Significant difference was found for most age levels in automaticity in migrant children compared to the DEM norms (independent t tests p < 0.05 DEM vertical and horizontal). However, few differences in eye movement coordination was found (p > 0.05 DEM ratios and errors). The data supports the hypothesis that language barriers inherent in this population are reflected by lower automaticity, but not eye movement dysfunction, as measured by the DEM. The results are important for optometrists because they demonstrate the importance of taking language and cognitive development into account before diagnosing eye movement dysfunction in culturally different children.