Evaluation of Leak Sites in Central Serous Chorioretinopathy and the Effects of PDT on RPE by Polarization-Sensitive OCT.

Purpose: The purpose of this study was to identify leak sites in central serous chorioretinopathy (CSCR) using polarization-sensitive optical coherence tomography (PS-OCT) and evaluate effects of photodynamic therapy (PDT) on morphological changes of retinal pigment epithelium (RPE). Methods: Ophthalmological examinations, including visual acuity, fluorescence angiography (FA), indocyanine green angiography (ICGA), swept-source OCT (SS-OCT), and PS-OCT, were performed. Polarimetric entropy (PE) of RPE was accessed in the area corresponding to the leak site identified by FA. Fluorescein intensity of the leak and area were evaluated. Aggregate of the low entropy area corresponding to the leak site was calculated. In eyes treated with PDT, PS-OCT imaging was performed 3 months after the treatment. Results: Fifty-one leak sites from 36 eyes of 31 patients with CSCR were included. Twenty eight eyes of 26 patients were treated with PDT. The mean age of the patients was 55.2 ± 11.5 years. Twenty-five eyes (69.4%) presented with a single leak and 11 eyes (30.6%) showed multiple leaks. A total of 377 low-entropy areas were detected by PS-OCT. Forty-five RPE defects (88.2%) were found in the leak sites, whereas 15 defects (29.4%) were found by SS-OCT (P < 0.0001). The overall positive predictive value was 11.9%. Area aggregate of the RPE defect was positively correlated with leak intensity at 1 minute and leak area at 1 and 4 minutes (P < 0.0001, = 0.0067, 0.0022, respectively). PDT significantly reduced the RPE defect area (P = 0.0025). Conclusions: PS-OCT identified leak sites in CSCR eyes more effectively than conventional OCT. PS-OCT is a noninvasive imaging modality to evaluate leak sites and the RPE-driven therapeutic process. Translational Relevance: This study establishes PS-OCT as a dye-free alternative to FA for identifying and monitoring leak sites in CSCR, with direct implications for safer clinical management.