Materials and Methods: Fifteen patients who underwent half-fluence PDT for chronic central serous chorioretinopathy between 2018- 2020 were included in the study retrospectively. Patients underwent optic coherence tomography angiography imaging before and after PDT. Foveal avascular zone (FAZ) area, FAZ perimeter, acircularity index, foveal vascular density 300 microns around FAZ, outer retina flow, choriocapillaris flow and the whole area, foveal, parafoveal and perifoveal vessel densities of superficial and deep capillary networks were compared before and after treatment.

Results: The vessel density of the superficial foveal capillary plexus was significantly decreased after PDT (p=0.044). However whole area, parafoveal and perifoveal vessel densities of superficial capillary plexus were not significantly different. The vessel density of the deep parafoveal capillary plexus was significantly increased after PDT (p=0.027). The whole area, foveal and perifoveal vessel densities of deep capillary plexus were not significantly different before and after PDT (p>0.05). Foveal avascular zone (FAZ) area, FAZ perimeter, acircularity index, outer retina flow and choriocapillaris flow did not change after photodynamic therapy in short term.

Conclusion: This study showed that vessel density of superficial foveal capillary plexus was decreased and vessel density of deep parafoveal capillary plexus was increased in short term after half fluence PDT. However, the foveal avascular zone area, ourter retinal and choroidal flow, choroidal signal voids and vascular densities of other remaining macular vascular areas were not changed. Keywords : photodynamic therapy, chronic central serous chorioretinopathy, choroid, retinal vessel