Comparisons of choroidal thickness and volume in eyes with central serous chorioretinopathy to that of control eyes determined by ultra-widefield optical coherence tomography.

Purpose: To compare choroidal thickness and volume in eyes with central serous chorioretinopathy (CSC) and healthy control eyes over a wide area of the fundus using ultra-widefield optical coherence tomography (UWF-OCT).

Methods: Thirty-three eyes of 29 patients with CSC and 36 eyes of 21 healthy controls were examined retrospectively. Choroidal images were obtained with a prototype UWF-OCT device with a field of view of 105° or approximately 31.5-mm wide by 10.9-mm deep. Choroidal thickness and volume were measured in the images of 12 radial scans (every 15°) from the horizontal scan. The "new index" of the extent of focal choroidal protrusion was defined as the maximum steepness of choroidal thickness (MSCT).

Results: Choroidal volume in CSC eyes was significantly larger than in control eyes within the central 50° (P < 0.001). However, there was no significant difference in choroidal volume in the peripheral 50 to 105° (P = 0.071). The MSCTs were significantly steeper in CSC eyes than in control eyes at scan lines 1, 6, 7, 8, and 10 (P < 0.01, P < 0.001, P < 0.05, P < 0.01, P < 0.05).

Conclusions: The choroid in CSC eyes was thickened only at the posterior pole, and its protrusion was significant mainly in the vertical direction. Focal choroidal thickening at the posterior pole, which we speculate includes congenital scleral changes, may affect the pathophysiology of CSC.