Analysis of fundus fluorescein angiography, indocyanine green angiography and choroidal thickness in central serous chorioretinopathy

Abstract

To evaluate the characteristics of choroidal thickness changes and abnormalities in choroidal circulation in cases of central serous chorioretinopathy (CSC). This was a case control study, we measured the bilateral choroidal thickness in 21 patients with unilateral CSC and 24 eyes of 24 age- and sex-matched normal subjects using enhanced depth imaging optical coherence tomography (EDI-OCT). The choroid was measured from the posterior edge of the retinal pigment epithelium (RPE) to the choroid-scleral junction at 500 µm intervals of a horizontal section from 3 mm temporal to the fovea to 3 mm nasal to the fovea. Paired-samples t-test was conducted to compare mean choroidal thicknesses between symptomatic eyes and fellow eyes of patients. The datum between patients and normal subjects were analyzed by independent-samples t-test. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed and the digital images were analyzed in CSC patients. The 21 CSC patients had a mean age of 45.6 years, and 12 patients (57.1%) were male. The choroid in symptomatic eyes was thickest beneath the fovea (519.0 ± 102.5) µm. It was significantly thicker than that in the fellow eyes (439.3 ± 94.1) µm (t = 4.171, P < 0.05). Choroidal thickness in both groups was significantly greater than that in the eyes of age- and sex-matched normal subjects (332.0 ± 67.3) µm (t = 7.125, 4.441; P < 0.05). Choroidal thickness at each of the other 12 points showed a similar tendency (t = 2.544 to 3.819, 4.799 to 7.816, 2.487 to 5.236; P < 0.05). ICGA showed a choroidal filling delay (100%), vessels dilation (90.5%), and focal choroidal hyperfluorescence (100%) surrounding leakage from the RPE in symptomatic eyes. Pigment epithelium detachment with abnormal choroidal circulation was observed in 6 fellow eyes. In 4 symptomatic eyes and 11 fellow eyes, ICGA revealed choroidal hyperfluorescence but FFA showed normal appearance. CSC seems to be a bilateral eye disease with choroidal focal ischemia followed by vessels congestion and hyperpermeability. EDI OCT is a useful tool for monitoring choroidal thickness changes caused by choroidal vascular hyperpermeability.