- Study Overview:
- Retrospective cross-sectional study comparing choroidal layer thickness beneath flat irregular pigment epithelial detachments (FIPEDs) in uncomplicated chronic central serous chorioretinopathy (uCSC) versus CSC complicated by type 1 macular neovascularization (cCSC).
- Included 94 treatment-naïve eyes (45 uCSC, 49 cCSC) using swept-source optical coherence tomography (SS-OCT).
- Key Definitions:
- FIPEDs: Shallow, irregular retinal pigment epithelium (RPE) elevations associated with CSC, often harboring type 1 macular neovascularization (MNV).
- uCSC: Chronic CSC without MNV; cCSC: CSC with confirmed type 1 MNV via fluorescein angiography (FA), indocyanine green angiography (ICGA), and OCT angiography (OCTA).
- Choroidal Layer Measurements:
- Measured choriocapillaris-Sattler layer complex thickness (SLCCT) and Haller’s layer thickness (HLT) beneath FIPEDs in central segments of three equal divisions.
- SLCCT significantly thinner in cCSC (47.2 ± 18.6 μm) vs uCSC (81.4 ± 22.4 μm, p=0.002).
- HLT significantly thinner in cCSC (265.3 ± 45.8 μm) vs uCSC (334.5 ± 43.2 μm, p=0.008).
- Total choroidal thickness reduced in cCSC (312.5 ± 51.2 μm) vs uCSC (415.9 ± 54.8 μm, p=0.002).
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Clinical Implications:
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Progressive choroidal thinning may be a biomarker for neovascular transformation in CSC, aiding in identifying eyes at risk for MNV.
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Thinning of choriocapillaris-Sattler complex suggests inner choroidal ischemia as a potential driver of type 1 MNV, similar to mechanisms in age-related macular degeneration (AMD) but with distinct pachychoroid-driven pathophysiology.
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- Diagnostic Tools:
- SS-OCT and SS-OCTA (PLEX Elite 9000) used for high-resolution imaging of choroidal layers and MNV detection.
- MNV confirmed by correlating SS-OCTA (en-face 6×6-mm scans) with ICGA (early, mid, and late phases).
- Intervortex anastomoses (non-tapering vessels crossing vortex vein territories) assessed but not significantly different between groups (44.4% uCSC vs 53.1% cCSC, p=0.12).
- Study Population:
- Mean age: 54.3 ± 8.4 years (uCSC) vs 56.1 ± 7.9 years (cCSC, p=0.28).
- Disease duration: 8.4 ± 2.6 months (uCSC) vs 11.2 ± 3.1 months (cCSC, p=0.08).
- Best-corrected visual acuity (BCVA): 0.22 ± 0.12 logMAR (uCSC) vs 0.30 ± 0.14 logMAR (cCSC, p=0.18).
- PED dimensions similar: height (98.2 ± 24.5 μm uCSC vs 92.8 ± 22.9 μm cCSC, p=0.26); width (884 ± 221 μm uCSC vs 842 ± 198 μm cCSC, p=0.45).
- Pathophysiology Insights:
- Chronic compression of choriocapillaris by dilated Haller’s vessels (pachyvessels, present in 91.1% uCSC and 87.8% cCSC) may lead to ischemia, promoting MNV.
- cCSC shows more severe choriocapillaris-Sattler attenuation and Haller’s layer thinning, indicating choroidal remodeling as a feature of neovascular progression.
- Limitations:
- Cross-sectional design limits temporal causality (choroidal thinning vs MNV onset).
- Manual segmentation of choroidal layers prone to variability, though interobserver agreement was excellent (ICC=0.92).
- Focused only on areas beneath FIPEDs, not broader macular regions.
- One-dimensional PED measurements used instead of volumetric analysis.
- Future Directions:
- Longitudinal studies to determine if choroidal thinning precedes or follows MNV.
- Automated segmentation algorithms for standardized measurements.
- Topographical analysis of choroidal changes across macular regions.
- Correlation of choroidal thinning with visual outcomes.
- Comparison to AMD:
- Type 1 MNV in cCSC has unique features (less exudative, distinct growth patterns) compared to AMD, driven by pachychoroid pathophysiology (choroidal congestion, RPE dysfunction) vs AMD’s outer retina/RPE dysfunction and immune processes.
Citation
Viggiano, P., Moscara, F., Termite, A. C., Boscia, G., La Terza, M., Salvelli, A., Pignataro, M. G., Porreca, A., Alessio, G., Behar-Cohen, F., & Boscia, F. (2025). Choroidal Layer Analysis Under Flat Irregular Pigment Epithelial Detachments in Central Serous Chorioretinopathy. American Journal of Ophthalmology. https://doi.org/10.1016/j.ajo.2025.04.005