Purpose
To determine if optical coherence tomography (OCT) angiography can detect abnormal choriocapillaris blood flow in central serous chorioretinopathy (CSC) compared to a group of normal controls.
Methods
Five eyes of 5 study participants with CSC (1 acute, 4 chronic) and 5 eyes of 5 normal controls were scanned with a spectral domain OCT (RTVue XR; 70 kHz scanning speed). Macular angiograms (3x3 mm, 6x6 mm) were obtained using the spit-spectrum amplitude decorrelation angiography (SSADA) algorithm, which detects areas of flow in otherwise static tissue. The volumetric angiogram was segmented into inner retinal, outer retinal, and choriocapillaris (10 microns below BM). Color-coded OCT cross sections allowed for representation of both flow and structure (purple = inner retina flow, red = outer retina flow). Vessel density (VD) of the choriocapillaris was the percentage of pixels with detectable flow in the segmented en face choriocapillaris angiogram. Statistical analysis included calculation of mean ± standard deviation and the Mann Whitney U test for group comparison.
Results
Mean choriocapillaris VD in the 3x3 mm scan was significantly reduced in CSC subjects (93.93% ± 3.99%) compared to normals (98.64% ± 0.61%), P<0.009. En face OCT angiograms in normal participants revealed relatively homogenous choriocapillaris flow. CSC subjects had patchy areas of decreased flow, which correlated to regions of hypo-cyanescence on indocyanine green angiography (ICGA). Hyperfluorescent staining and leakage on fluorescein angiography (FA) correlated to most, but not all, areas of reduced choriocapillaris flow.
Conclusions
OCT angiography detected reduced choriocapillaris vessel density in CSC subjects compared to normal controls. Patchy areas of reduced flow were visible on en face choriocapillaris angiograms. Further study of the choriocapillaris with OCT angiography may improve understanding of CSC pathogenesis.