Study finds, Decrease in choroidal blood flow after 1/2 and
This study aimed to evaluate choroidal blood flow after half-dose photodynamic therapy (1/2PDT) and one-third dose PDT (1/3PDT) with verteporfin for chronic serous chorioretinopathy (CSC) using laser speckle flowgraphy and spectral-domain optical coherence tomography.

27 eyes of 27 patients with serous retinal detachment (SRD) caused by chronic CSC for more than 6 months were included in this study. Patients were divided into the 1/2PDT (n=12) and 1/3PDT (n=15) groups based on the treatment period. The best-corrected visual acuity (BCVA), central retinal thickness (CRT), central choroidal thickness (CCT), and mean blur rate in the macular area (m-MBR) and optic nerve head (ONH-MBR) were obtained using laser speckle flowgraphy and evaluated at baseline (pre-treatment), and 2 weeks, 1 month, 3 months, and 6 months after treatment.

--SRD disappeared after 1 month in 92 and 93% of patient's eyes in the 1/2PDT and 1/3PDT groups, respectively.

--Recurrence of SRD was observed in one eye at the 6-month follow-up after 1/2PDT and two eyes at the 3-month follow-up after 1/3PDT.

--No significant improvement was observed in baseline BCVA in the 1/3PDT and 1/2PDT groups.

--The average m-MBR against baseline significantly decreased at 2weeks and 1, 3, and 6months in the 1/2PDT group.

--The average m-MBR against baseline decreased significantly only at the 2weeks follow-up in the 1/3PDT group.

--The average rate of change in the CCT against baseline decreased significantly throughout for up to 6 months in the 1/2PDT group and for up to 3months in the 1/3PDT group. No significant fluctuation was observed in the ONH-MBR.

Conclusively, In chronic CSC, PDT had a considerable effect on choroidal blood flow, depending on the verteporfin dose.