The Evaluation of Change in Choroidal Circulation Time before and after Half-Dose Photodynamic Therapy in Central...

Background: Indocyanine green angiography (ICGA) is often used for diagnosis of, and as an indication to apply laser treatment for, central serous chorioretinopathy (CSC). Although photodynamic therapy (PDT) is effective against CSC, the details of the mechanism are unknown. To verify the effect of PDT, we compared the time of choroidal circulation before and after PDT in CSC patients, using ICGA. Methods: Seven eyes of seven patients (six male, one female) who were diagnosed with chronic CSC associated with serous retinal detachment (SRD) in the macular area and who underwent half-dose PDT were included. Wide-field ICGA images with an angle of 102° were taken and evaluated at the superior and inferior temporal quadrants. Choroidal circulation time (CCT) was defined as the time from the start of contrast filling in the choroidal artery to the first appearance of contrast filling in the temporal vortex vein ampulla. Results: The average CCT before and after PDT in the superior temporal vortex vein was 3.96 s and 5.41 s (p = 0.018), and 4.12 s and 5.02 s (p = 0.046) in the inferior temporal vortex vein, respectively. All SRD and choroidal vascular hyperpermeability areas dissolved after PDT. Conclusions: In this pilot study, half-dose PDT prolonged CCT in CSC patients, indicating the effect of selective vascular obstruction in the choriocapillaris.