Purpose: To evaluate the variability in subfoveal choroidal thickness measurements in patients with age-related macular degeneration (AMD) and central serous chorioretinopathy using enhanced depth imaging optical coherence tomography (EDI-OCT).
Methods: One hundred and sixty eyes of 160 patients who were diagnosed with early AMD (N=40), exudative AMD (N=40), polypoidal choroidal vasculopathy (PCV, N=40), or central serous chorioretinopathy (CSC, N=40) were included in this retrospective observational study. In addition, we included 40 normal eyes of 40 subjects. Subfoveal choroidal thickness was measured manually by two masked observers based on EDI-OCT images. The correlation of choroidal thickness with the absolute value of the difference in the choroidal thickness measurement was estimated for all 200 eyes. Intraobserver and interobserver coefficients of repeatability (CRs) were calculated.
Results: There was a significant positive correlation between subfoveal choroidal thickness and both intraobserver (P<0.001) and interobserver (P<0.001) difference in choroidal thickness measurements. The mean intraobserver CRs in nonexudative AMD, exudative AMD, PCV, CSC, and normal eyes were ~15-21, 23-29, 24-35, 32-38, and 19-25 μm, respectively. The mean interobserver CRs were ~24-28, 30-36, 39-45, 46-57, and 26-35 μm, respectively.
Conclusions: Relatively great measurement variability should be considered when investigating eyes with pathologic conditions related to a thick choroid, including PCV or CSC.