Choroidal vascularity changes in idiopathic central serous chorioretinopathy after half-fluence photodynamic therapy.

After HF-PDT, the choriocapillaris showed the earliest decrease in vascular proportion of en face images, Sattler's and Haller's layers showed later decreases. The temporal differences in the response of each layer may reflect the pathophysiology of CSC and the therapeutic mechanism of HF-PDT.