Relationship between visual skills and performance on saccadic eye movement testing

The effect of visual skills, such as binocularity, on saccadic eye movement test performance is currently unknown. Therefore, the relationship between performance on commonly used clinical saccadic eye movement tests and visual skill was studied in a masked investigation of 181 kindergartners and first graders (mean age 6.25 years) from a middle class, suburban, elementary school near Cleveland, Ohio. The New York State Optometric Association King-Devick saccade test (NYSOA K-D) and the Developmental Eye Movement test (DEM) were employed because they are two commonly used clinical saccadic eye movement tests. A Modified Clinical Technique (MCT) vision screening and Randot stereoacuity test were performed to evaluate other visual skills. Analysis revealed that for the whole study population, total errors on the NYSOA K-D were significantly related to referral on the MCT screening (p = 0.015) and stereoacuity worse than 100 sec arc (p = 0.011). A trend toward significance was also found between DEM ratio and stereoacuity worse than 50 sec arc for the whole study population. However, in the children who passed the MCT, stereoacuity was not found to be significantly related to performance on NYSOA K-D or DEM. Thus, our findings indicate that visual difficulties may affect performance on the NYSOA K-D in this population.