A reevaluation of the Developmental Eye Movement (DEM) test's repeatability

Abstract

Purpose: To investigate the repeatability of the Developmental Eye Movement (DEM) Test in a group of third grade elementary school students.

Methods: Thirty, third grade children who passed a modified clinical technique vision screening were given the DEM and then retested 2 weeks later.

Results: A clinically and statistically significant improvement in mean scores from test to retest was found on the vertical time, horizontal time, and ratio score. The intraclass correlation coefficient (ICC) and the 95% limits of agreement (LoA) suggest that the vertical (ICC, 0.60; LoA, -4.2 +/- 16.5 s) and corrected horizontal (ICC, 0.55; LoA, -8.3 +/- 17.4 s) times have fair to good repeatability, whereas the ratio score was found to have poor repeatability (ICC, 0.27; LoA, -0.08 +/- 0.39). Based on these results, large changes can be expected on retest, which may result in a change in diagnostic classification from pass to fail.

Conclusions: These results suggest that the ratio score of the DEM had poor repeatability in the third grade children who were evaluated. Poor repeatability of the ratio score may affect the clinician's diagnostic decisions and ability to monitor the effects of saccadic treatment.