Wide-Field Swept-Source OCT Analysis of Interocular Symmetry of Choroidal Thickness in Subjects with Uncomplicated Pachychoroid

Background: We aimed to study the bilateral choroidal thickness (CT) symmetry and difference in uncomplicated pachychoroid subjects using wide-field swept-source optical coherence tomography (SS-OCT). Methods: All subjects underwent a wide-field 16-mm one-line scan using SS-OCT. Bilateral CT was measured at, and compared among, the following 12 points: three points at 900-mu m intervals from the nasal optic disc margin (nasal peripapillary area), one point at the subfovea, six points at 900-mu m intervals from the fovea to the nasal and temporal areas (macular area), and two peripheral points 5400 and 8100 mu m from the fovea (peripheral area). Results: There were no statistically significant differences in CT between the right and left eyes in any area (all p > 0.05); they all showed significant positive correlations (all p < 0.01). However, the correlation coefficients (rho) were smaller for the nasal peripapillary and peripheral areas compared to the macular area. Conclusions: The CTs in each region were bilaterally symmetrical in subjects with uncomplicated pachychoroid. However, interocular difference in CT increased from the center to the periphery, indicating that the anatomical variation of the nasal peripapillary and peripheral choroid was greater than that of the macula.