Choroidal abnormalities in central serous chorioretinopathy

Purpose: To evaluate choroidal abnormalities in acute (A–ChCSC) and chronic (C–ChCSC) central serous chorioretinopathy evaluated with dynamic indocyanine green angiography (d–ICGA). Methods: We examined 40 consecutive patients with A–ChCSC or C–ChCSC. Dynamic fluorescein angiography (d–FA) and indocyanine green angiography (d–ICGA) were performed by means of a confocal scanning laser ophthalmoscope (Heidelberg HRA – Heidelberg Engineering Germany) using 1 ml of mixed solution obtained with 200 mg of fluorescein and 10 mg of indocyanine green, followed by 5 cc of saline flush. d–FA was used to confirm the diagnosis and d–ICGA to analyze the choroidal flow and characteristics. Two independent observers evaluated the early and late phase of the angiographies. Results: d–ICGA shows different characteristics in A–ChCSC and in C–ChCSC. In A–ChCSC the most evident abnormality is the choroidal filling delay (8 out 15 – 53%) present not only in the area of the fluorescein leakage. In A–ChCSC transient multifocal dilatations of choroidal veins are evident (80%), not always related to the site of serous detachment. In C–ChCSC a diffuse and stable dilations of the veins are visible during the venous phase and usually correspond to the area of the retinal pigment epithelium decompensation (22 out 25 – 88%). In the late phase intrachoroidal leakage is present in A–ChCSC and C–ChCSC. Conclusions:The different choroidal abnormalities visualized in A–ChCSC and C–ChCSC seem to suggest a different mechanism in these two diseases. The presence of choroidal dilation in C–ChCSC could explain the effect of photodynamic therapy as suggest by different authors.