Domitest-S: A Novel Dichoptic Technique to Assess Ocular Sensory Dominance in Children: A Population Study

Abstract

Aims: To assess sensory ocular dominance of children by means of a novel psychophysical technique (Domitest-S). Study Design: population study. Place and Duration of Study: Department of Ophthalmology, The Gradenigo Hospital, Turin, between June 2012 and June 2013. Methodology: Thirty sequences of stimuli (15 for the left eye and 15 for the right eye) were administered in dichoptic conditions to 152 pupils (mean age: 9 ± .8 years). The task was to detect the target (a checkerboard-like pattern arranged so as to form an “X”) embedded in a series of null stimuli (checkerboard-like patterns randomly arranged). Left and right proportion correct responses were computed and an index of dominance laterality, the Balance Value (BV), expressed as the right minus left proportion correct responses was introduced. A second index based on the total amount of percent correct responses, the Interocular Inhibitory Index (III) was computed to provide a measure of reciprocal binocular suppression. Results: The frequency distribution of sensory dominance was not normal, but skewed on the left (KS=.17, P<.001). The median was .20 (range .00-.80) with 77% of the subjects showing a BV between .00 and .27. A substantial equivalence was found between the proportion of right and left dominants (46%). Balance values ranging from –.20 to +.27 accounted for 79% of the variance. The distribution of the reciprocal interocular suppression measured as III was bimodal, showing two peaks, one on the right (lower inter-inhibitory effect) and the other on the left (stronger inter-inhibitory effect). Test-retest reliability was acceptable (correlation between the left and right correct responses at first and second examination: Spearman r= .54, P< .001). The duration of the examination was about 5 minutes. Conclusion: Domitest-S proves to be a fast and reliable technique to assess sensory dominance in children within the clinical setting