Relationship between oculomotor scanning determined by the DEM test and a contextual reading test in schoolchildren with reading difficulties

The relationship between oculomotor scanning and reading in poor readers of primary school age is not well known. This study was designed to assess this relationship by determining mean Developmental Eye Movement (DEM) test times and reading speeds in a Spanish non-clinical population of children with poor reading skills but without dyslexia. We conducted a cross-sectional study on 81 poor readers (8-11 years of age) in the third to fifth grades recruited from 11 elementary schools in Madrid, Spain. In each subject with best spectacle correction, oculomotor scanning was measured using the DEM test, and reading speed (words per minute) was assessed by a standardized Spanish contextual reading test. Mean horizontal DEM times were higher than normative values for children in the third, fourth and fifth grades, by 20 seconds, 12 seconds, and 3 seconds respectively. Mean reading speeds were 18 words per minute lower than the norm for the third and fourth grades respectively, and 30 words per minute lower than the norm for the fifth grade. Reading speeds were significantly related to horizontal DEM times (r = -0.53, p < 0.0001). Thus, children showing a longer, or worse, horizontal DEM time achieved lower reading speeds. Poor readers showed poor horizontal scanning as assessed by the DEM test that was related to a slow reading speed. This test should be used by optometric clinicians as a screening tool to help identify poor reading skills in school children at an early stage.