PURPOSE

To investigate variations in choroidal thickness and morphology in the eyes of Chinese adults with anisometropic myopia and their relationship with myopia.

METHODS

This study included 107 adults (aged 17-50 years) with myopia and normal visual acuity. Based on interocular differences in spherical equivalent (SE), participants were categorized into an anisometropia group (≥ 1 diopter, [D], N = 33) and a control group (< 1D, N = 74). Optical coherence tomography was used to measure ocular biometry and choroidal thickness at seven horizontal regions, extending from nasal (N) to temporal (T). These regions included the subfoveal region, 0.5 mm (T/N0.5), 1.5 mm (T/N1.5), and 2.5 mm (T/N2.5) from the subfoveal. A proposed fitting curve equation described the choroidal curvature.

RESULTS

Binocular choroidal thickness exhibited a decreasing trend from temporal to nasal regions, with slight thickening in the subfoveal region compared to choroidal thickness at T0.5 and N0.5 in both groups ( < 0.01). In the anisometropia group, lower myopic eyes had greater choroidal thickness than those with higher myopia ( < 0.05). Fitting curve analysis revealed that eyes with lower myopia exhibited greater choroidal curvature than those with higher refractive power within the anisometropia group ( = 0.021). Additionally, choroidal thickness at parafoveal locations positively correlated with SE and negatively correlated with axial length in all eyes ( < 0.05).

CONCLUSION

In adults with myopia, choroidal thickness shows a decreasing trend from temporal to nasal region and is negatively correlated with myopia degree. Morphological flattening in anisometropic eyes suggests choroid remodeling for axial adaptation elongation.