Saccadic eye movements in childhood: A pilot study comparing clinical eye tracker software and the NSUCO

To explore differences in saccadic eye movements between children with oculomotor dysfunction and those in a control group across three age groups, using two assessment methods: the subjective Northeastern State University College of Optometry (NSUCO) Oculomotor test and objective analysis with the Tobii Eye X Eye Tracker (Tobii Eye X, Tobii, Stockholm, Sweden).

This study included 31 children (ages 7-13) diagnosed with oculomotor dysfunction and 16 age-matched children in the control group. Participants were divided into three age groups: group 1 (7-8 years), group 2 (9-11 years), and group 3 (12-13 years). Saccadic eye movements were evaluated and compared using two methods: the NSUCO test and the Tobii Eye X eye tracker, along with specialized software analysis (Thomson Software Solutions, Welham Green, UK) RESULTS: Children in the oculomotor dysfunction group obtained significantly lower NSUCO scores (p < 0.001) compared to the control group. Regarding eye tracking analyses, a significantly higher number of hypometric saccades were found in oculomotor dysfunction group (p ≤ 0.044). Additionally, in this group a significantly higher percentage of regressions was observed for a 1-second stimulus presentation interval (p = 0.012). Significant correlations were found between different NSUCO scores and the percentage of regressions, the number of completed saccades and the number of hypometric saccades.

The presence of hypometric saccades and regressions appears to be a distinguishing characteristic of children with oculomotor dysfunction, detectable through both objective eye tracking analysis and the subjective NSUCO test, which can be easily implemented in clinical settings.