Polarimetric Entropy in Hypoautofluorescent Lesions of Central Serous Chorioretinopathy: Association with...

To quantify the spatial correspondence between near-infrared autofluorescence (NIRAF) and polarimetric-entropy (PE) maps in central serous chorioretinopathy (CSC), and to compare PE metrics between simple and complex subtypes.

In this cross-sectional study, 53 patients (87 eyes) with CSC who underwent NIRAF and polarization-sensitive optical coherence tomography (PS-OCT) imaging were analyzed. Patchy hypo-autofluorescent lesions (HAFLs) on NIRAF and hypo-entropic lesions (HELs) on retinal pigment epithelium PE maps were segmented. Spatial correspondence between HAFLs and HELs was assessed with Dice coefficients. Lesion area, absolute PE, and relative PE loss (normalized to surrounding area) were compared across modalities and between simple versus complex CSC.

Ninety-five HAFLs and 101 HELs were identified. Ninety-two HAFL-HEL pairs (97% of HAFLs; 91% of HELs) overlapped, with a mean Dice coefficient of 0.76 and mean sensitivity of 0.89; 9% of HELs lacked a NIRAF counterpart. Absolute PE correlated with NIRAF intensity (P = 0.017; R2 = 0.071). After normalization, the correlation improved (R2 = 0.20). Compared with simple CSC, complex CSC exhibited larger lesion areas (P < 0.001) and deeper PE loss (relative PE 71% vs 76%; P = 0.049).

Polarimetric entropy identifies almost all NIRAF-dark lesions and provides an RPE-layer-specific, melanin-related depolarization metric on a continuous scale. Complex CSC is characterized by broader involvement and greater PE loss, consistent with more severe RPE dysfunction. PE may complement extent-based classification. Prospective longitudinal studies are needed to investigate its utility for monitoring and prognostication.