Morphological differences of choroid in central serous chorioretinopathy determined by ultra-widefield optical coherence tomography.

Purpose: The purpose of this study was to compare the morphology of the central and peripheral choroid of eyes with central serous chorioretinopathy (CSC) to that of normal eyes using ultra-widefield optical coherence tomography (UWF-OCT).

Methods: We reviewed the medical records of 29 eyes of 25 patients (23 men, 2 women; average age 44.4 years) with CSC and 34 eyes of 22 healthy subjects (19 men, 3 women; average age, 49.5 years) with normal eyes. The images obtained by a prototype swept source UWF-OCT (Topcon, Tokyo, Japan) of about 31.5-mm wide and a depth of 10.9 mm were analyzed. The choroidal thickness was measured for each sector of the eye using the conventional automated layer analysis method. The local morphological differences were quantified by the maximum steepness (µm/deg) which was obtained by differentiating the changes in the choroidal thickness from the periphery to the fovea. Only the vertical scans were evaluated to avoid the influence of the optic disc.

Results: The choroid was thicker in the macular area than the peripheral area in both normal and CSC eyes. The choroid at the subfovea was significantly thicker in the CSC eyes than that of the normal eyes (P < 0.0001); however, the difference at the periphery was not significant. The mean of the maximum steepness of the choroidal thickness was 20.8 ± 3.8 µm/deg in the CSC eyes which was significantly steeper than the 16.0 ± 4.6 µm/deg in healthy eyes (P < 0.0001).

Conclusion: The choroid in CSC eyes has a steeper slope around the posterior pole. UWF-OCT can be used to evaluate the abnormalities of the choroidal structures from the posterior pole to the periphery in eyes with CSC.