To measure choroidal thickness in healthy myopic eyes and to evaluate the relationship among choroidal thickness and refractive power and axial length.

Eighty healthy myopic eyes were evaluated in the present study. The refractive power was measured using an automatic refractor and the axial length using A-scan. The subjects were divided into two groups based on refractive power (≥-6.0 D and <-6.0 D) and axial length (≥25 mm and <25 mm). The choroidal thickness was measured using spectral domain (SD) optical coherence tomography (3-dimensional [3D] OCT-2000, Software Version 6.01; Topcon Corp., Tokyo, Japan), and the statistical relationship between the two groups was analyzed.

A statistically significant difference was found in choroidal thickness according to refractive power and axial length between the two groups ( p < 0.001 and p < 0.05, respectively).

Refractive power and axial length had a significant relation to choroidal thickness measured by OCT. When excluding eyes with pathologic myopia, high myopia in healthy eyes may cause choroidal thinning.