Developmental Eye Movement Test: reliability and symptomatology.

Background: The Developmental Eye Movement Test (DEM) is a widely used visual skill test, especially in the context of a vision therapy evaluation. It is intended to diagnose oculomotor dysfunction (OMD) and can also identify deficient rapid automatized naming. As such, its reliability and associated symptomatology are important.

Methods: The DEM test-retest reliability was investigated within two populations: a group of 53 office patients who were participating in vision therapy evaluation in a private optometry practice, and a smaller group of 13 subjects at their school. One to four weeks separated the test and retest for both groups. We also studied the relationship between results on a questionnaire of symptoms associated with OMD and DEM test performance in these two populations.

Results: The first administration of the DEM significantly correlated with the second for all four of its scores for both groups. The office group had higher intra-class correlation coefficients than the school group. There was good agreement between test and re-test in terms of pass-fail classification for the office group. Symptomatic subjects performed poorer than asymptomatic subjects on the DEM. Failing the DEM Ratio, the score used to diagnose OMD, identified 90% of the subjects who were symptomatic.

Conclusions: The DEM has good intra-subject test-retest reliability for all four of its scores when it is administered in an office setting to patients participating in a vision therapy evaluation. It also has good consistency in classifying patients as pass or fail. Performance on the DEM relates to certain symptoms that are associated with OMD.