Choroidal Layer Analysis Under Flat Irregular Pigment Epithelial Detachments in Central Serous Chorioretinopathy

Purpose: To compare choroidal layer thickness beneath flat irregular pigment epithelial detachments (PEDs) between uncomplicated chronic central serous chorioretinopathy (uCSC) and CSC complicated by type 1 macular neovascularization (cCSC). Design: Retrospective cross-sectional study. Methods: This retrospective study included 94 treatment-naïve eyes (45 uCSC, 49 cCSC) with flat irregular PEDs. Using swept-source optical coherence tomography, we measured choriocapillaris-Sattler layer complex thickness and Haller's layer thickness beneath the PEDs. Measurements were performed in the central segments of three equal divisions under each PED. Results: Mean Sattler layer complex thickness was significantly lower in cCSC compared to uCSC (47.2 ± 18.6 µm vs 81.4 ± 22.4 µm, P = .002). Similarly, Haller's layer thickness was reduced in cCSC (265.3 ± 45.8 µm vs 334.5 ± 43.2 µm, P = .008). Other characteristics, including age (56.1 ± 7.9 vs 54.3 ± 8.4 years, P = .28), disease duration (11.2 ± 3.1 vs 8.4 ± 2.6 months, P = .08), and PED dimensions were comparable between groups. Conclusions: cCSC eyes show significant thinning of both the choriocapillaris-Sattler complex and Haller's layer under flat irregular PEDs compared to uCSC eyes. These findings suggest that progressive choroidal thinning may be a key feature of neovascular transformation and could serve as a potential biomarker to identify eyes at risk for neovascular complications.