Abstract
Purpose: :
To investigate the association between spatial distribution of choroidal thickness and ocular axial length, refractive error, gender, and age in healthy subjects using 2 spectral domain optical coherence tomography (SD-OCT) instruments: Zeiss Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA), Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany).
Methods: :
Sixty eyes of 30 healthy dilated volunteers without ocular pathology were imaged on the fovea using Cirrus 1-line raster and Spectralis enhanced depth imaging (EDI). Choroidal thickness was measured subfoveally, 1.5 mm temporal, and 1.5 mm nasal to the fovea by 2 independent graders. Student’s t-test, Pearson correlation, and Bland-Altman analysis were used for statistical analyses.
Results: :
The group of 30 subjects consisted of 15 men and 15 women. The mean age was 50.4 years (range, 14-75 years). There was no significant difference in the mean choroidal thickness (P> 0.05) between systems for any location. Increasing axial length (p=0.007) and decreasing refractive error (p=0.003) positively correlated with the difference between subfoveal and temporal choroidal thickness, which was calculated by subtraction of subfoveal thickness from temporal thickness.
Conclusions: :
There was a good reproducibility between choroidal thickness measurements obtained with Cirrus and Spectralis. Myopic changes (longer axial length and decreasing refractive error) were associated with increased temporal choroidal thickness with respect to subfoveal choroidal thickness.
Keywords: choroid • imaging/image analysis: clinical • myopia