Effect of amblyopia treatment on choroidal thickness in hypermetropic anisometropic amblyopia using swept-source optical coherence tomography

BACKGROUND: Recent studies using optical coherence tomography (OCT) have indicated that choroidal thickness (CT) in the anisometropic amblyopic eye is thicker than that of the fellow and normal control eyes. However, it has not yet been established as to how amblyopia affects the choroid thickening. The purpose of the present study was to investigate the effect of amblyopia treatment on macular CT in eyes with anisometropic amblyopia using swept-source OCT. METHODS: Thirteen patients (mean age: 6.2 ± 2.4 years) with hypermetropic anisometropic amblyopia were included in this study. Visual acuity (VA), axial length (AL), and CT were measured at the enrollment visit and at the final visit, after at least 6 months of treatment. CT measurements were corrected for magnification error and were automatically analyzed using built-in software and divided into three macular regions (subfoveal choroidal thickness (SFCT), center 1 mm, and center 6 mm). A one-way analysis of covariance using AL as a covariate was performed to determine whether CT in amblyopic eyes changed after amblyopia treatment. RESULTS: The average observation period was 22.2 ± 11.0 months. After treatment, VA (logMAR) improvement in the amblyopic eyes was 0.41 ± 0.19 (p < 0.001). SFCT, center 1 mm CT, and center 6 mm CT were significantly thicker in the amblyopic eyes compared with the fellow eyes both before and after treatment (p < 0.05 for all comparisons). There were no significant changes in SFCT, center 1 mm CT, or center 6 mm CT before and after treatment in the amblyopic (p = 0.25, 0.21, and 0.84, respectively) and fellow (p = 0.75, 0.84, and 0.91, respectively) eyes. The correlation between changes in logMAR versus changes in CT after treatment was not significant. CONCLUSIONS: Although VA in amblyopic eyes was significantly improved after treatment, the choroid thickening of anisometropic amblyopic eyes persisted, and there was no significant change found in the CT after the treatment. Our findings suggest that thickening of the CT in amblyopia is not directly related to visual dysfunction.