Evaluation of Choroidal Thickness in Amblyopia Using Enhanced Depth Imaging Optical Coherence Tomography

To evaluate the choroidal thickness (CT) in hyperopic anisometropic amblyopic eyes, fellow non-amblyopic eyes, and age-matched normal eyes, using spectral-domain optical coherence tomography (SD-OCT).

In total 53 subjects (17.8 ± 11.0 years, mean ± SD) with hyperopic anisometropic amblyopia (AE) and 53 age-matched controls (17.7 ± 11.0 years) were included in this prospective study. Each subject underwent a dilated eye examination, cycloplegic refraction and axial length (AL) measurement using Nidek AL-Scan optical biometer (Nidek CO, Aichi, Japan). The CT of subfoveal area and at a radius of 1 and 3 mm around the fovea was determined using the enhanced depth imaging program of a SD-OCT (Cirrus HD OCT, Carl-Zeiss Meditec, Dublin, CA). CT, AL and spherical equivalent refraction (SER) of the amblyopic eyes were compared to that of the fellow and control eyes.

The mean subfoveal CT was 305.6 ± 26.0 µm in the amblyopic eyes, 282.6 ± 30.7 µm in the fellow eyes and 280.1 ± 8.8 in the control eyes. The subfoveal choroid in amblyopic eyes was significantly thicker than that of the fellow eyes and control eyes (p <  0.001). There was a significant negative correlation between the subfoveal CT and the AL in amblyopic (r = -0.298, p=0.03) eyes but not in the control and fellow eyes.

The subfoveal choroid of eyes with hyperopic AE is significantly thicker than that of the fellow eye and the age-matched controls. Hence, CT seems to be effected in AE.