Does the treatment of amblyopia normalise subfoveal choroidal thickness in amblyopic children?

Recent studies have found a choroidal thickening in amblyopic eyes and suggested that there might be a relationship between the choroid and amblyopia. The present study aimed to evaluate the effect of a six-month treatment of amblyopia on choroidal thickness in anisometropic hyperopic amblyopic children.

Thirty-two anisometropic hyperopic children with unilateral amblyopia were included in this prospective study. Subfoveal choroidal thickness was measured as the distance between the retinal pigment epithelium and the chorioscleral edge, by using spectral domain enhanced depth imaging optical coherence tomography. The treatment of amblyopia was performed based on the full correction of the refractive error with eyeglasses, a refractive adaptation phase and occlusion by patching the fellow eye.

The mean visual acuity of the amblyopic eyes significantly increased from 0.35 ± 0.3 to 0.16 ± 0.2 logMAR after the treatment (p < 0.001). The mean initial choroidal thickness was significantly higher in the amblyopic eyes than in the fellow eyes (p = 0.019). There were no significant differences between the pre- and post-treatment mean choroidal thickness in the amblyopic eyes (p = 0.428) and in the fellow eyes (p = 0.343). The mean choroidal thickness was still higher in the amblyopic eyes than in the fellow eyes after the treatment (p = 0.006).

Although a six-month treatment of amblyopia increased the visual acuity of the anisometropic hyperopic amblyopic eyes, it could not significantly change choroidal thickness. Our results were in accordance with the conventional explanation, which suggests visual cortex and lateral geniculate nucleus abnormalities in the pathophysiology of amblyopia.