To determine changes in retinal and choroidal capillaries with optical coherence tomographic angiography (OCTA) after half-dose photodynamic therapy (hd-PDT) in eyes with central serous chorioretinopathy (CSC).

PDT was hypothesized to have a primary effect on the choroidal capillaries, and a number of studies have reported choriocapillary damage and choroidal vascular remodeling after PDT. More recently, although OCTA related CSC research has been conducted, no quantitative report has thoroughly investigated the microstructural changes in the superficial, deep retinal and choroidal capillaries after hd-PDT. The purpose of the present study is to determine the changes in the retinal and choroidal capillaries quantitatively with OCTA after hd-PDT in eyes with CSC.

This is a prospective observational study of patients undergoing hd-PDT for CSC with active leakage in retinal pigment epithelium (RPE) and followed for 3 months. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed at baseline; best corrected visual acuity (BCVA), fundus photography, optical coherence tomography angiography (OCTA) with the split-spectrum amplitude-decorrelation angiography algorithm (XR Optovue, Fremont, CA, USA) and spectral domain OCT (SD-OCT) were performed at baseline and each follow-up visit after hd-PDT.

Inclusion Criteria:

1. CSC diagnosed by FFA and ICGA, where the active leakage was just located in macular fovea with SRF confirmed by OCT
2. Patient age ≥18 years
3. BCVA ≥35 letters on ETDRS charts
4. Persistent CSC for a period of time or patients were anxiety about the symptom and asking for treatment
5. Lack of either spontaneous improvement or improvement induced by empirical treatment such as pharmaceutical drug
6. The provision of written informed consent -

Exclusion Criteria:

1. The presence of any other chorioretinal diseases that may affect the studies, such as age-related macular degeneration (AMD), polypoidal choroidal vasculopathy (PCV)
2. Patients who had received any previous treatment, including PDT, intraocular drug injection or focal thermal laser photocoagulation for CSC
3. Patients with PED in macular fovea which the average diameter (transverse diameter and vertical diameter) was more than 300 microns
4. Patients with high myopia, defined as a refractive error (spherical equivalent) < -6.00 diopters, or an axial length >26.5 mm
5. Patients with media opacities, or signal strength index of the images < 60
6. Patients under corticosteroid therapy -

Patients with Central Serous Chorioretinopathy (CSC)