To evaluate objectively the accommodative response in patients who have intermittent exotropia with a dominant eye.

Observational cohort study.

setting: Institutional. patients: One hundred thirty-three patients younger than 15 years, including 33 patients with intermittent exotropia and equal dominance, 54 patients with intermittent exotropia with a dominant eye, and 46 patients with orthotropia or exophoria of less than 10 prism diopters. observation: A Shin-Nippon NVision-K 5001 autorefractor was used to measure the accommodative response under binocular and monocular viewing conditions at 33 cm. Patients wore spectacles to achieve distant refractive errors within 0.50 diopter in both eyes. main outcome measures: Accommodative responses of each eye in binocular and monocular viewing conditions were compared between fellow eyes and groups.

During binocular viewing, 65% of nondominant eyes showed an accommodative lag of more than 0.5 diopter, whereas 40% of dominant eyes showed an accommodative lead. In contrast, 77% of the eyes in the equal dominance group and 59% of the normal group showed an accommodative lag of less than 0.5 diopter. During binocular viewing, patients with dominant eye intermittent exotropia showed significantly more asymmetry in the accommodative response between both eyes than patients with equal dominance intermittent exotropia and normal controls (P = .001). During monocular viewing, there was no significant difference in asymmetry between the 3 groups (P = .059).

Patients with intermittent exotropia with a dominant eye tend to have asymmetric accommodative responses between both eyes during binocular viewing, where the nondominant eye showed a decreased accommodative response.