To compare the choroidal thickness of unaffected and affected eyes in children with unilateral high myopia when measured using enhanced depth imaging and to analyze the relationship among choroidal thickness and axial length, spherical equivalent and best corrected visual acuity (BCVA).

Twenty children with high unilateral high myopia who received optical coherence tomography from December 2012 to May 2014 were retrospectively analyzed. Choroidal thickness was measured with a caliper at 500 µm apart from fovea superiorly and inferiorly, 2,500 µm apart nasally and at 2,500 µm apart temporally at 500 µm intervals. For statistical analyses, paired t -test was used for choroidal thickness and linear regression analysis for the relationship among choroidal thickness and axial length, spherical equivalent and BCVA.

The patients were 10.4 ± 3.5 years of age and the average BCVA of myopic eye was 0.38 ± 0.2. Mean spherical equivalent was -9.8 ± 1.9D. The choroidal thickness was significantly thinner in the myopic eye (102.5 ± 16.9 µm) than the fellow eye (282.9 ± 14.0 µm). The thickest choroid in the myopic eye was the temporal and the thinnest was the nasal area ( p = 0.008). Choroidal thickness was significantly associated with axial length and spherical equivalent but not BCVA.

Highly myopic eyes tend to have thinner choroidal thickness than the fellow eyes and choroidal thickness tends to be thicker temporally. Therefore, several anatomical changes in unilateral highly myopic children may exist.