The presumed influence of attention on accuracy in the developmental eye movement (DEM) test

Background: The developmental eye movement (DEM) test is a clinical test us ed widely to evaluate ocular motility function (accuracy and speed) in scho ol-age children. Purpose: The purpose of this study was to investigate, ret rospectively, the change in accuracy over time while performing the DEM hor izontal reading task in children. Methods: The charts from children who had performed the DEM test during a routine eye examination in a pediatric opt ometry service were reviewed. The study included 22 patients (6 to 11 years old, 12 boys, 10 girls) who had a routine eye examination that was precept ed by one of the authors (R.C.) during the period of 1995 to 1999. Patients were divided into two categories: 1) those with abnormal DEM test results and 2) a control group consisting of those with normal DEM test results. Ch art review was done consecutively within each category. Collected data incl uded patient age, gender, refractive error, and DEM test results. For analy sis, the horizontal task of the DEM was divided into two halves (I and II), Part I always preceded part II, and data was sorted as the number of error s per part. Results: More errors in accuracy occurred in part 11 than in pa rt I (Wilcoxon signed rank test, p less than or equal to 0.01) of the horiz ontal DEM test in the group of subjects with an abnormal DEM test. No diffe rences in the number of errors in parts I and II of the horizontal task of the DEM were found in the control group. Conclusions: Findings showed that when excessive errors in accuracy occurred, the number of errors increased over time. If the errors were caused by an oculomotor dysfunction found in the DEM, errors should be equally distributed throughout the text. If error s were caused by fatigue, a difference in parts I and II should have occurr ed in both the test and the control group. These findings suggest that atte ntion may influence accuracy over time in those patients that do poorly on the DEM test.