Abstract:  Objective To compare the differences in fixative eye movements and saccadic eye movements between children with intermittent exotropia and normal children. Design Case-control study. Participants Children attending the strabismus and amblyopia outpatient clinic at West China Hospital, including 31 cases of intermittent exotropia and 22 normal children. Methods All subjects watched the screen at a distance of 80 cm from the computer display screen, and used the visual biological information stimulation technology-enhanced vision eye tracker software, and used its augmented reality technology to collect and analyze binocular fixation and saccadic eye movements. Tobii Eye Tracker 5 4C eye tracking device captures the orientation and trajectory of eyeball movement, and it was performed under corrected state for those with ametropia. Main Outcome Measures Corrected visual acuity, refractive error, prism diopters of strabismus, horizontal deviation of fixation point, vertical deviation of fixation point. Results In terms fixation eye movement, significant differences were observed between the intermittent exotropia group and the normal group in the directions of upper-right, straight-right, and lower-left gaze. The deviations of fixation points were significant in the horizontal direction for straight-right (Z=-2.764, P=0.006) and in the vertical direction for lower-left (Z=-2.112, P=0.035), while both horizontal (Z=-2.266, P=0.023) and vertical deviations (Z=-2.113, P=0.035) were significant for upper-right gaze points. In terms of saccadic eye movement, the intermittent exotropia group glanced at the beginning of the first line (Z=-2.140, P=0.032) and the end of the line (Z=-2.573, P=0.010), the beginning of the second line (Z=- 2.907, P=0.004) and the end of the line (Z=-2.365, P=0.018), the end of the third line (Z=-3.268, P=0.001), the beginning of the fourth line (Z=-2.022, P=0.043), there was an obvious offset in the horizontal direction; when scanning the first line (Z=-2.527, P=0.011) and the end of the line (Z=-2.031, P=0.042), the third line end (Z=-2.257, P=0.024), and the fourth row head (Z=-2.826, P=0.005), the intermittent exotropia group had a significant shift in the vertical direction. In the third row, there were significant differences in the vertical deviation of fixation positions at the beginning and end of the row (Z=-2.858, P=0.004). Conclusion Children with intermittent exotropia have different degrees of impairment in both fixation eye movement and saccadic eye movement compared to normal children. (Ophthalmol CHN, 2023, 32: 310-315)

Key words:  , intermittent exotropia, fixation eye movement, saccadic eye movement