A Tool for Saccadic Evaluation in Adults

The Developmental Eye Movement test (DEM), is standardized and designed for evaluating oculomotor behavior in children, under 14 years of age. In this study we sought to create a version to be used above the age of 14 by using double rather than single digits. This resulted in twice the amount of numbers to be called out during the test. We administered this modified version for adults (A-DEM) to 520 normal Spanish-speaking subjects ranging from 14 to 68 years of age. They were divided into 11 age groups. The subjects were assessed to be cognitively intact with no known neurological or ocular disease. All subjects had corrected visual acuity of 20/20 or better at near and viewed the targets binocularly. The times (in seconds) to call out the numbers in Spanish in for the vertical and horizontal subtests were recorded. Errors were also recorded. A horizontal/vertical (HV) ratio was determined based on these results. The mean (HV) ratio for the sample was 1.04(0.10) with no significant difference due to age . A significant increase in time for vertical performance was found in subjects older than 38 years (p<0.05) and for horizontal performance in subjects older than 43 years (p<0.05). There was no significant difference in the ratio as a function of age. We present the age-based normative values for our sample. We also found changes in horizontal saccade ability with an apparent tendency to take longer as age increased in later decades of life. The potential affect of ageing on visual-verbal and eye movement processing are discussed. Further studies are needed for this adult level oculomotor test in English-speaking populations as well as selected elderly pop-