To determine central retinal thickness and subfoveal choroidal thickness using optical coherence tomography (OCT) and to evaluate association between both thickness and age, gender and axial length.Methods
Spectral domain OCT images (Bioptigen, Bioptigen, inc., Durham, NC) were obtained in 151 eyes of 151 healthy volunteers without retinal diseases. The IOL master (Carl Zeiss Meditech) was used to measure the eye length to compensate axial scale factor of the SD-OCT images. The choroidal thickness at the fovea and central retinal thickness was measured. Statistical analysis using paired t-test and Pearson correlation were performed to evaluate the correlation between both thickness and age, axial length, and gender.Results
The mean and median age of the 151 subjects were 33.3 and 29 years old, respectively (range, 7 to 80 years). There were 57 males and 94 females. The mean and median axial lengths of the eye were 24.54±0.98 mm and 24.37 mm respectively. The mean central retinal thickness were 213.89±14.64μm. Increasing age and axial length were not correlated with central retinal thickness. The mean choroidal thickness in these normal eyes was 214.43±13.63μm. Increasing age (Pearsun correlation - 0.193, R2=-0.0372, p=0.018) and increasing axial length (Pearsun correlation - 0.189, R2=-0.0359, p=0.020) were correlated with decreasing choroidal thickness. Central retinal thickness and subfoveal choroidal thickness have no relationship between them in our study (Pearsun correlation - 0.139, R2=0.0192, p=0.090 ).Conclusion
Only the choroidal thickness at the fovea in normal eyes showed an inverse correlation with age and axial length. And there is no significant relationship between central retinal thickness and subfoveal choroidal thickness.