Dilatation of Asymmetric Vortex Vein in Central Serous Chorioretinopathy

To characterize the outer choroidal vessels in normal control eyes and those with central serous chorioretinopathy (CSC).

Prospective case-control study.

Thirty-eight eyes of 35 patients with acute CSC and 39 age-matched normal subjects.

Swept-source optical coherence tomography was performed to obtain B-scan and en face images in the posterior pole in both groups. All patients with CSC underwent fluorescein angiography (FA) and indocyanine green angiography (ICGA).

Ascertainment of the patterns of the outer choroidal vessels in the en face and B-scan images in normal controls and patients, and the relationship between the en face images and dye leakage in the FA images and hyperpermeability in the ICGA images.

En face and ICGA images showed 2 choroidal drainage routes that served the upper and lower halves of the posterior pole. Twenty-four of the 39 eyes (62%) of the normal subjects had symmetrically distributed outer choroidal vessels; 15 eyes (38%) had asymmetrically distributed outer choroidal vessels. Asymmetry was seen in all 38 eyes (100%) of the 35 patients with CSC. The outer choroidal vessels all had vortex veins on en face and ICGA images. In eyes with CSC, a dominant vortex vein served the macular region (9 eyes) or the posterior pole (24 eyes) or extended beyond the vascular arcades (5 eyes). Dominant vortex veins were relatively dilated in normal controls but dilated markedly in CSC, with the distal ends in the macular region abruptly dilated. The sites of dye leakage on the FA images and hyperpermeability on the ICGA images corresponded to the dilated dominant vortex veins.

The presence of an asymmetric vortex vein was a common variation (38%) in normal subjects; this asymmetry was seen in all eyes (100%) with CSC. Dominant vortex veins were dilated markedly in CSC. Congestion of the dominant vortex veins might enhance the permeability of fenestrated choriocapillaris in the macular region. Asymmetric dominant vortex veins appear to be a predisposing factor for CSC.