Interocular transfer of a visual aftereffect in early-onset esotropia

The interocular transfer of the tilt aftereffect was studied in strabismic patients with early-onset esotropia and in controls. Squinting subjects were divided into a microtropia subgroup with anomalous binocular vision and a large-angle esotropia subgroup with total suppression of the deviated eye. Patients with alternating microtropia and large-angle esotropia showed normal or moderately reduced interocular transfer of the aftereffect. Patients with monocular microtropia with medium- or low-degree amblyopia showed a reduced monocular visual aftereffect in the dominant eye and practically no transfer to the nondominant eye. Adaptation of the nondominant eye and transfer of the aftereffect to the dominant eye was normal. The interocular transfer of the tilt aftereffect is a poor indicator of the state of binocularity of a squinting subject, and the clinical usefulness of this test is limited.