Anisometropic amblyopia: axial length versus corneal curvature in children with severe refractive imbalance

To define the ocular parameters associated with anisometropic ambylopia in children with severe hyperopia, myopia, or astigmatism in 1 eye.

Anisometropic and fellow eyes of 13 children, ages 7-8, with anisometropia >3.0 D and amblyopia without strabismus or other visually significant ocular pathology were studied. Axial length, corneal curvature, anterior chamber depth, and corneal diameter measurements of amblyopic and fellow eyes were obtained using the IOL Master (Carl Zeiss Meditec, Dublin, CA).

Comparing amblyopic eyes with unaffected fellow eyes as reference, patients with anisohyperopia had shorter axial lengths by an average of 1.49 mm (p = 0.001), and patients with anisomyopia had longer axial lengths by an average of 2.26 mm. Corneal astigmatism was the source of amblyogenic refractive error in 1 child.

In children with anisometropic amblyopia, interocular differences in spherical refractive error was attributed to axial length with no differences in corneal curvature, whereas the anisoastigmatism observed in 1 case was attributed to asymmetric corneal curvature.