PURPOSE:To determine the maturational course of nasotemporal asymmetry in infantile esotropia and to define the relationships among the symmetry of the motion visual evoked potential (MVEP), eye alignment, fusion, and stereopsis.METHODS:Sixty healthy term infants and 34 infants with esotropia participated. Nasotemporal MVEP asymmetry was assessed by the presence of a significant F1 response component with an interocular phase difference of approximately 180 degrees and by an amplitude "asymmetry index." Fusion was evaluated using the 4 p.d. base out prism test. Random dot stereoacuity was assessed in infants with forced-choice preferential looking (FPL) using the Infant Random Dot Stereocards. Eye alignment was assessed by the alternate prism and cover or the modified Krimsky test.RESULTS:Normal infants 2 to 3 months of age exhibited marked nasotemporal MVEP asymmetry, which rapidly diminished by 6 to 8 months. Neonates did not exhibit MVEP asymmetry. There was good concordance between fusion and MVEP symmetry and between stereopsis and MVEP symmetry; the concordance between MVEP symmetry and orthoposition of the visual axes was significantly poorer. The same proportion of normal and young esotropic infants showed symmetrical MVEPs. Regardless of the age at surgery, most patients with infantile esotropia had asymmetrical MVEPs after surgery.CONCLUSIONS:These data support a strong link between fusion and MVEP symmetry during both normal maturation and in infantile esotropia. Furthermore, the finding that the youngest infants with esotropia do not differ significantly from normal suggests that the nasotemporal asymmetry found in older patients with infantile esotropia does not represent an arrest of maturation but, rather, a pathologic change of the motion pathways.

Purpose: Despite successful optical realignment, many children with accommodative esotropia (ET) have abnormal stereoacuity. In a prospective study, we examined the influence of age of onset, age at alignment, duration of constant misalignment, and accommodative convergence/accommodation ratio on random dot stereoacuity outcomes in accommodative ET. Methods: Participants were 111 consecutive children with accommodative ET. Random dot stereoacuity was measured using the Randot preschool stereoacuity test, the Randot stereoacuity test, the infant random dot stereoacuity cards, and the Lang 1. Results: Age of onset has only a minor influence on stereoacuity (P <.02); children with onset ≥age 25 months have better stereoacuity compared with children with an onset between ages 7 and 17 months. Age at alignment has a minor influence on stereoacuity (P <.001); children with intermittent ET who have been treated have better stereoacuity than children with a constant ET aligned between ages 6 and 24 months and after age 24 months. Duration of constant misalignment has the strongest influence on stereoacuity (P <.00l); children who had intermittent misalignment or who had a constant misalignment of less than 4 months' duration have better stereoacuity than patients who had a constant misalignment greater than 4 months' duration. The accommodative convergence/accommodation ratio does not influence stereoacuity outcomes (P >.10). Conclusions: Fine random dot stereoacuity is associated with a constant misalignment of less than 4 months' duration. These findings promote prompt and aggressive treatment of accommodative ET at the onset of intermittent or constant misalignment. (J AAPOS 2000;4:15-20)

PURPOSE. TO quantify motion sensitivity in patients with infantile esotropia who, as a subgroup, have been previously reported to have abnormal oculomotor control. In addition, to probe abnormal binocular development as a factor underlying abnormal motion perception in infantile esotropia (IE), motion sensitivity was compared among participants with and without stereopsis.METHODS. Monocular sensitivity to leftward and rightward motion was assessed across the horizontal meridian, using partially coherent random dot kinematograms. Participants included 11 observers with IE, 5 observers with acquired esotropial and 11 observers with normal eye alignment.RESULTS. Participants with IE showed no deficits in motion sensitivity to any visual field locations when motion thresholds were collapsed across direction. However, they showed an abnormal variation in directional anisotropy. Although sensitivity to centripetal motion was superior in both hemifields of control participants and in the temporal hemifields of participants with IE, a centrifugal bias was revealed in the nasal hemifields of LE. Stereoblind observers with acquired esotropia showed a normal centripetal directional anisotropy, whereas binocular observers with acquired esotropia showed directional anisotropy similar to that in the IE group.CONCLUSIONS. Motion perception, like oculomotor function in IE, is characterized by a variation of directional anisotropy for stimuli presented to the nasal hemifields. This finding supports the hypothesis that abnormal oculomotor control and motion perception in IE reflect a common disruption of the visual system. A similar variation of directional sensitivity in patients with acquired esotropia with normal stereopsis suggests that the interruption of binocularity is not the underlying cause of abnormal motion perception in IE.