Characteristics of horizontal saccades in children with intermittent exotropia

Purpose: To analyze the peak velocity and gain of horizontal saccades in children diagnosed with intermittent exotropia (IXT) and to compare these measurements with those obtained from children without strabismus. Methods: Participants included children ≤12 years of age with IXT and no history of strabismus surgery and children without strabismus. The peak velocity and gain of horizontal saccades recorded using an eye tracker were analyzed. Results: A total of 48 children (including 38 with IXT) were included. In the IXT group, the angles of deviation at near were 30.3^Δ ± 13.5^Δ; at distance, 30.6^Δ ± 10.5^Δ. Stereopsis was ≤60 arcsec in 29 patients and 80–400 arcsec in 9 patients. In the IXT group, the peak velocity and gain of the adduction saccade tended to be greater than those of the abduction saccade, but not significantly. The no-strabismus group exhibited a similar trend, with a stronger tendency in the dominant eye, reaching statistical significance. Conclusions: Both the children with IXT and children without strabismus showed a dominance of adduction in their saccades; however, this dominance was weaker in children with IXT.