Clinical study of the effect of refractive status on stereopsis in children with intermittent exotropia

Many studies have shown that patients with intermittent exotropia have different degrees of damage to their stereopsis function. The purpose of this study is to explore the effect of different refractive status on stereopsis in children with intermittent exotropia(IXT).

We assessed 90 children of ages 4~ 16 years with intermittent exotropia at the Second Affiliated Hospital of Dalian Medical University during the years 2016-2017. According to their refractive status, the patients were divided into hyperopia group(spherical equivalent > or = - 1.00 diopters), myopia group(spherical equivalent < or = - 1.00 diopters), emmetropia group (spherical equivalent diopter: within ±1.00DS) and anisometropia group(binocular equivalent spherical difference > or = 1.50 diopter). The distant stereopsis of the patient was checked by the synoptophore, and the near stereopsis of the patients was checked by the Titmus stereogram. Then, we compared the difference between distant stereopsis and near stereopsis in the four groups.

(1)The retention rates of distant stereopsis in the hyperopia group, emmetropia group, myopia group and anisometropia group were 33.3, 45.2, 34.6, and 33.3%, respectively. There was no significant difference between the groups with different refractive status. (2)The retention rates of near stereopsis in the hyperopia group, emmetropia group, myopia group and anisometropia group were 66.7, 83.9, 80.8, and 55.6%, respectively. There were statistically significant differences between the emmetropia group and the anisometropia group (P = 0.030). (3)The retention rate of distant stereopsis in children with intermittent exotropia was 37.8%, and the retention rate of near stereopsis was 74.4%. The difference between the two groups was statistically significant (P = 0.019).

The damage to distant stereopsis in children with intermittent exotropia is more serious than that to near stereopsis. The damage to near stereopsis in children with intermittent exotropia and anisometropiais more serious.